Posts Tagged ‘Biotechnology and Pharmaceuticals’

37th Annual J.P. Morgan HEALTHCARE CONFERENCE: News at #JPM2019 for Jan. 10, 2019: Deals and Announcements

Reporter: Stephen J. Williams, Ph.D.



JP Morgan Healthcare Conference Update: Sage, Mersana, Shutdown Woes and Babies

Speaker presenting to audience at a conference

With the J.P. Morgan Healthcare Conference winding down, companies remain busy striking deals and informing investors about pipeline advances. BioSpace snagged some of the interesting news bits to come out of the conference from Wednesday.

SAGE Therapeutics – Following a positive Phase III report that its postpartum depression treatment candidate SAGE-217 hit the mark in its late-stage clinical trial, Sage Therapeutics is eying the potential to have multiple treatment options available for patients. At the start of J.P. Morgan, Sage said that patients treated with SAGE-217 had a statistically significant improvement of 17.8 points in the Hamilton Rating Scale for Depression, compared to 13.6 for placebo. The company plans to seek approval for SAGE-2017, but before that, the FDA is expected to make a decision on Zulresso in March. Zulresso already passed muster from advisory committees in November, and if approved, would be the first drug specifically for postpartum depression. In an interview with the Business Journal, Chief Business Officer Mike Cloonan said the company believes there is room in the market for both medications, particularly since the medications address different patient populations.


Mersana Therapeutics – After a breakup with Takeda Pharmaceutical and the shelving of its lead product, Cambridge, Mass.-based Mersana is making a new path. Even though a partial clinical hold was lifted following the death of a patient the company opted to shelve development of XMT-1522. During a presentation at JPM, CEO Anna Protopapas noted that many other companies are developing therapies that target the HER2 protein, which led to the decision, according to the Boston Business Journal. Protopapas said the HER2 space is highly competitive and now the company will focus on its other asset, XMT-1536, an ADC targeting NaPi2b, an antigen highly expressed in the majority of non-squamous NSCLC and epithelial ovarian cancer. XMT-1536 is currently in Phase 1 clinical trials for NaPi2b-expressing cancers, including ovarian cancer, non-small cell lung cancer and other cancers. Data on XMT-1536 is expected in the first half of 2019.

Novavax – During a JPM presentation, Stan Erck, CEO of Novavax, pointed to the company’s RSV vaccine, which is in late-stage development. The vaccine is being developed for the mother, in order to protect an infant. The mother transfers the antibodies to the infant, which will provide the baby with protection from RSV in its first six months. Erck called the program historic. He said the Phase III program is in its fourth year and the company has vaccinated 4,636 women. He said they are tracking the women and the babies. Researchers call the mothers every week through the first six months of the baby’s life to acquire data. Erck said the company anticipates announcing trial data this quarter. If approved, Erck said the market for the vaccine could be a significant revenue driver.

“You have 3.9 million birth cohorts and we expect 80 percent to 90 percent of those mothers to be vaccinated as a pediatric vaccine and in the U.S. the market rate is somewhere between $750 million and a $1 billion and then double that for worldwide market. So it’s a large market and we will be first to market in this,” Erck said, according to a transcript of the presentation.

Denali Therapeutics – Denali forged a collaboration with Germany-based SIRION Biotech to develop gene therapies for central nervous disorders. The two companies plan to develop adeno-associated virus (AAV) vectors to enable therapeutics to cross the blood-brain barrier for clinical applications in neurodegenerative diseases including Parkinson’s, Alzheimer’s disease, ALS and certain other diseases of the CNS.

AstraZeneca – Pharma giant AstraZeneca reported that in 2019 net prices on average across the portfolio will decrease versus 2018. With a backdrop of intense public and government scrutiny over pricing, Market Access head Rick Suarez said the company is increasing its pricing transparency. Additionally, he said the company is looking at new ways to price drugs, such as value-based reimbursement agreements with payers, Pink Sheet reported.

Amarin Corporation – As the company eyes a potential label expansion approval for its cardiovascular disease treatment Vascepa, Amarin Corporation has been proactively hiring hundreds of sales reps. In the fourth quarter, the company hired 265 new sales reps, giving the company a sales team of more than 400, CEO John Thero said. Thero noted that is a label expansion is granted by the FDA, “revenues will increase at least 50 percent over what we did in the prior year, which would give us revenues of approximate $350 million in 2019.”

Government Woes – As the partial government shutdown in the United States continues into its third week, biotech leaders at JPM raised concern as the FDA’s carryover funds are dwindling. With no new funding coming in, reviews of New Drug Applications won’t be able to continue past February, Pink Sheet said. While reviews are currently ongoing, no New Drug Applications are being accepted by the FDA at this time. With the halt of NDA applications, that has also caused some companies to delay plans for an initial public offering. It’s hard to raise potential investor excitement without the regulatory support of a potential drug approval. During a panel discussion, Jonathan Leff, a partner at Deerfield Management, noted that the ongoing government shutdown is a reminder of how “overwhelmingly dependent the whole industry of biotech and drug development is on government,” Pink Sheet said.

Other posts on the JP Morgan 2019 Healthcare Conference on this Open Access Journal include:

#JPM19 Conference: Lilly Announces Agreement To Acquire Loxo Oncology

36th Annual J.P. Morgan HEALTHCARE CONFERENCE January 8 – 11, 2018

37th Annual J.P. Morgan HEALTHCARE CONFERENCE: #JPM2019 for Jan. 8, 2019; Opening Videos, Novartis expands Cell Therapies, January 7 – 10, 2019, Westin St. Francis Hotel | San Francisco, California

37th Annual J.P. Morgan HEALTHCARE CONFERENCE: News at #JPM2019 for Jan. 8, 2019: Deals and Announcements



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Kurzweill Reports in Medical Science I

Curator: Larry H. Bernstein, MD, FCAP




E-coli bacteria found in some China farms and patients cannot be killed with antiobiotic drug of last resort

“One of the most serious global threats to human health in the 21st century” — could spread around the world, requiring “urgent coordinated global action”
November 20, 2015

Colistin antibiotic overused in farm animals in China apparently caused E-coli bacteria to become completely resistant to treatment; E-coli strain has already spread to Laos and Malaysia (credit: Yi-Yun Liu et al./Lancet Infect Dis)

Widespread E-coli bacteria that cannot be killed with the antiobiotic drug of last resort — colistin — have been found in samples taken from farm pigs, meat products, and a small number of patients in south China, including bacterial strains with epidemic potential, an international team of scientists revealed in a paper published Thursday Nov. 19 in the journal The Lancet Infectious Diseases.

The scientists in China, England, and the U.S. found a new gene, MCR-1, carried in E-coli bacteria strain SHP45. MCR-1 enables bacteria to be highly resistant to colistin and other polymyxins drugs.

“The emergence of the MCR-1 gene in China heralds a disturbing breach of the last group of antibiotics — polymixins — and an end to our last line of defense against infection,” said Professor Timothy Walsh, from the Cardiff University School of Medicine, who collaborated on this research with scientists from South China Agricultural University.

Walsh, an expert in antibiotic resistance, is best known for his discovery in 2011 of the NDM-1 disease-causing antibiotic-resistant superbug in New Delhi’s drinking water supply. “The rapid spread of similar antibiotic-resistant genes such as NDM-1 suggests that all antibiotics will soon be futile in the face of previously treatable gram-negative bacterial infections such as E.coli and salmonella,” he said.

Likely to spread worldwide; already found in Laos and Malaysia

The MCR-1 gene was found on plasmids — mobile DNA that can be easily copied and transferred between different bacteria, suggesting an alarming potential to spread and diversify between different bacterial populations.

Structure of plasmid pHNSHP45 carrying MCR-1 from Escherichia coli strain SHP45 (credit: Yi-Yun Liu et al./Lancet Infect Dis)

“We now have evidence to suggest that MCR-1-positive E.coli has spread beyond China, to Laos and Malaysia, which is deeply concerning,” said Walsh.  “The potential for MCR-1 to become a global issue will depend on the continued use of polymixin antibiotics, such as colistin, on animals, both in and outside China; the ability of MCR-1 to spread through human strains of E.coli; and the movement of people across China’s borders.”

“MCR-1 is likely to spread to the rest of the world at an alarming rate unless we take a globally coordinated approach to combat it. In the absence of new antibiotics against resistant gram-negative pathogens, the effect on human health posed by this new gene cannot be underestimated.”

“Of the top ten largest producers of colistin for veterinary use, one is Indian, one is Danish, and eight are Chinese,” The Lancet Infectious Diseases notes. “Asia (including China) makes up 73·1% of colistin production with 28·7% for export including to Europe.29 In 2015, the European Union and North America imported 480 tonnes and 700 tonnes, respectively, of colistin from China.”

Urgent need for coordinated global action

“Our findings highlight the urgent need for coordinated global action in the fight against extensively resistant and pan-resistant gram-negative bacteria,” the journal paper concludes.

“The implications of this finding are enormous,” an associated editorial comment to the The Lancet Infectious Diseases paper stated. “We must all reiterate these appeals and take them to the highest levels of government or face increasing numbers of patients for whom we will need to say, ‘Sorry, there is nothing I can do to cure your infection.’”

Margaret Chan, MD, Director-General of the World Health Organization, warned in 2011 that “the world is heading towards a post-antibiotic era, in which many common infections will no longer have a cure and, once again, kill unabated.”

“Although in its 2012 World Health Organization Advisory Group on Integrated Surveillance of Antimicrobial Resistance (AGISAR) report the WHO concluded that colistin should be listed under those antibiotics of critical importance, it is regrettable that in the 2014 Global Report on Surveillance, the WHO did not to list any colistin-resistant bacteria as part of their ‘selected bacteria of international concern,’” The Lancet Infectious Diseases paper says, reflecting WHO’s inaction in Ebola-stricken African countries, as noted last September by the international medical humanitarian organization Médecins Sans Frontières.

Funding for the E-coli bacteria study was provided by the Ministry of Science and Technology of China and National Natural Science Foundation of China.

Abstract of Emergence of plasmid-mediated colistin resistance mechanism MCR-1 in animals and human beings in China: a microbiological and molecular biological study

Until now, polymyxin resistance has involved chromosomal mutations but has never been reported via
horizontal gene transfer. During a routine surveillance project on antimicrobial resistance in commensal Escherichia coli from food animals in China, a major increase of colistin resistance was observed. When an E coli strain, SHP45, possessing colistin resistance that could be transferred to another strain, was isolated from a pig, we conducted further analysis of possible plasmid-mediated polymyxin resistance. Herein, we report the emergence of the first plasmid-mediated polymyxin resistance mechanism, MCR-1, in Enterobacteriaceae.

The mcr-1 gene in E coli strain SHP45 was identified by whole plasmid sequencing and subcloning. MCR-1 mechanistic studies were done with sequence comparisons, homology modelling, and electrospray ionisation mass spectrometry. The prevalence of mcr-1 was investigated in E coli and Klebsiella pneumoniae strains collected from five provinces between April, 2011, and November, 2014. The ability of MCR-1 to confer polymyxin resistance in vivo was examined in a murine thigh model.

Polymyxin resistance was shown to be singularly due to the plasmid-mediated mcr-1 gene. The plasmid carrying mcr-1 was mobilised to an E coli recipient at a frequency of 10−1 to 10−3 cells per recipient cell by conjugation, and maintained in K pneumoniae and Pseudomonas aeruginosa. In an in-vivo model, production of MCR-1 negated the efficacy of colistin. MCR-1 is a member of the phosphoethanolamine transferase enzyme family, with expression in E coli resulting in the addition of phosphoethanolamine to lipid A. We observed mcr-1 carriage in E coli isolates collected from 78 (15%) of 523 samples of raw meat and 166 (21%) of 804 animals during 2011–14, and 16 (1%) of 1322 samples from inpatients with infection.

The emergence of MCR-1 heralds the breach of the last group of antibiotics, polymyxins, by plasmid-mediated resistance. Although currently confined to China, MCR-1 is likely to emulate other global resistance mechanisms such as NDM-1. Our findings emphasise the urgent need for coordinated global action in the fight against pan-drug-resistant Gram-negative bacteria.


Researchers discover signaling molecule that helps neurons find their way in the developing brain

November 20, 2015

This image shows a section of the spinal cord of a mouse embryo. Neurons appear green. Commissural axons (which connect the two sides of the brain) appear as long, u-shaped threads, and the bottom, yellow segment of the structure represents the midline (between brain hemispheres). (credit: Laboratory of Brain Development and Repair/ The Rockefeller University)

Rockefeller University researchers have discovered a molecule secreted by cells in the spinal cord that helps guide axons (neuron extensions) during a critical stage of central nervous system development in the embryo. The finding helps solve the mystery: how do the billions of neurons in the embryo nimbly reposition themselves within the brain and spinal cord, and connect branches to form neural circuits?

Working in mice, the researchers identified an axon guidance factor, NELL2, and explained how it makes commissural axons (which connect the two sides of the brain).

The findings could help scientists understand what goes wrong in a rare disease called horizontal gaze palsy with progressive scoliosis. People affected by the condition often suffer from abnormal spine curvature, and are unable to move their eyes horizontally from side to side. The study was published Thursday Nov. 19 in the journal Science.

Abstract of Operational redundancy in axon guidance through the multifunctional receptor Robo3 and its ligand NELL2

Axon pathfinding is orchestrated by numerous guidance cues, including Slits and their Robo receptors, but it remains unclear how information from multiple cues is integrated or filtered. Robo3, a Robo family member, allows commissural axons to reach and cross the spinal cord midline by antagonizing Robo1/2–mediated repulsion from midline-expressed Slits and potentiating deleted in colorectal cancer (DCC)–mediated midline attraction to Netrin-1, but without binding either Slits or Netrins. We identified a secreted Robo3 ligand, neural epidermal growth factor-like-like 2 (NELL2), which repels mouse commissural axons through Robo3 and helps steer them to the midline. These findings identify NELL2 as an axon guidance cue and establish Robo3 as a multifunctional regulator of pathfinding that simultaneously mediates NELL2 repulsion, inhibits Slit repulsion, and facilitates Netrin attraction to achieve a common guidance purpose.

A sensory illusion that makes yeast cells self-destruct

A possible tactic for cancer therapeutics
November 20, 2015


Effects of osmotic changes on yeast cell growth. (A) Schematic of the flow chamber used to create osmotic level oscillations for different periods of time. (B) Cell growth for these periods. The graphs show the average number of progeny cells (blue) before and after applying stress for different periods (gray shows orginal “no stress” line). The inset shows representative images of cells for two periods. (credit: Amir Mitchell et al./Science)

UC San Francisco researchers have discovered that even brainless single-celled yeast have “sensory biases” that can be hacked by a carefully engineered illusion — a finding that could be used to develop new approaches to fighting diseases such as cancer.

In the new study, published online Thursday November 19 in Science Express, Wendell Lim, PhD, the study’s senior author*, and his team discovered that yeast cells falsely perceive a pattern of osmotic levels (by applying potassium chloride) that alternate in eight minute intervals as massive, continuously increasing stress. In response, the microbes over-respond and kill themselves. (In their natural environment, salt stress normally gradually increases.)

The results, Lim says, suggest a whole new way of looking at the perceptual abilities of simple cells and this power of illusion could even be used to develop new approaches to fighting cancer and other diseases.

“Our results may also be relevant for cellular signaling in disease, as mutations affecting cellular signaling are common in cancer, autoimmune disease, and diabetes,” the researchers conclude in the paper. “These mutations may rewire the native network, and thus could modify its activation and adaptation dynamics. Such network rewiring in disease may lead to changes that can be most clearly revealed by simulation with oscillatory inputs or other ‘non-natural’ patterns.

“The changes in network response behaviors could be exploited for diagnosis and functional profiling of disease cells, or potentially taken advantage of as an Achilles’ heel to selectively target cells bearing the diseased network.”
UC San Francisco (UCSF) | Sensory Illusion Causes Cells to Self-Destruct

* Chair of the Department of Cellular and Molecular Pharmacology at UCSF, director of the UCSF Center for Systems and Synthetic Biology, and a Howard Hughes Medical Institute (HHMI) investigator.

** Normally, sensor molecules in a yeast cell detect changes in salt concentration and instruct the cell to respond by producing a protective chemical. The researchers found that the cells were perfectly capable of adapting when they flipped the salt stress on and off every minute or every 32 minutes. But to their surprise, when they tried an eight-minute oscillation of precisely the same salt level the cells quickly stopped growing and began to die off.

Abstract of Oscillatory stress stimulation uncovers an Achilles’ heel of the yeast MAPK signaling network

Cells must interpret environmental information that often changes over time. We systematically monitored growth of yeast cells under various frequencies of oscillating osmotic stress. Growth was severely inhibited at a particular resonance frequency, at which cells show hyperactivated transcriptional stress responses. This behavior represents a sensory misperception—the cells incorrectly interpret oscillations as a staircase of ever-increasing osmolarity. The misperception results from the capacity of the osmolarity-sensing kinase network to retrigger with sequential osmotic stresses. Although this feature is critical for coping with natural challenges—like continually increasing osmolarity—it results in a tradeoff of fragility to non-natural oscillatory inputs that match the retriggering time. These findings demonstrate the value of non-natural dynamic perturbations in exposing hidden sensitivities of cellular regulatory networks.

Google Glass helps cardiologists complete difficult coronary artery blockage surgery

November 20, 2015


Google Glass allowed the surgeons to clearly visualize the distal coronary vessel and verify the direction of the guide wire advancement relative to the course of the occluded vessel segment. (credit: Maksymilian P. Opolski et al./Canadian Journal of Cardiology

Cardiologists from the Institute of Cardiology, Warsaw, Poland have used Google Glass in a challenging surgical procedure, successfully clearing a blockage in the right coronary artery of a 49-year-old male patient and restoring blood flow, reports the Canadian Journal of Cardiology.

Chronic total occlusion, a complete blockage of the coronary artery, sometimes referred to as the “final frontier in interventional cardiology,” represents a major challenge for catheter-based percutaneous coronary intervention (PCI), according to the cardiologists.

That’s because of the difficulty of recanalizing (forming new blood vessels through an obstruction) combined with poor visualization of the occluded coronary arteries.

Coronary computed tomography angiography (CTA) is increasingly used to provide physicians with guidance when performing PCI for this procedure. The 3-D CTA data can be projected on monitors, but this technique is expensive and technically difficult, the cardiologists say.

So a team of physicists from the Interdisciplinary Centre for Mathematical and Computational Modelling of theUniversity of Warsaw developed a way to use Google Glass to clearly visualize the distal coronary vessel and verify the direction of the guide-wire advancement relative to the course of the blocked vessel segment.

Three-dimensional reconstructions displayed on Google Glass revealed the exact trajectory of the distal right coronary artery (credit: Maksymilian P. Opolski et al./Canadian Journal of Cardiology)

The procedure was completed successfully, including implantation of two drug-eluting stents.

“This case demonstrates the novel application of wearable devices for display of CTA data sets in the catheterization laboratory that can be used for better planning and guidance of interventional procedures, and provides proof of concept that wearable devices can improve operator comfort and procedure efficiency in interventional cardiology,” said lead investigatorMaksymilian P. Opolski, MD, PhD, of the Department of Interventional Cardiology and Angiology at the Institute of Cardiology, Warsaw, Poland.

“We believe wearable computers have a great potential to optimize percutaneous revascularization, and thus favorably affect interventional cardiologists in their daily clinical activities,” he said. He also advised that “wearable devices might be potentially equipped with filter lenses that provide protection against X-radiation.

Abstract of First-in-Man Computed Tomography-Guided Percutaneous Revascularization of Coronary Chronic Total Occlusion Using a Wearable Computer: Proof of Concept

We report a case of successful computed tomography-guided percutaneous revascularization of a chronically occluded right coronary artery using a wearable, hands-free computer with a head-mounted display worn by interventional cardiologists in the catheterization laboratory. The projection of 3-dimensional computed tomographic reconstructions onto the screen of virtual reality glass allowed the operators to clearly visualize the distal coronary vessel, and verify the direction of the guide wire advancement relative to the course of the occluded vessel segment. This case provides proof of concept that wearable computers can improve operator comfort and procedure efficiency in interventional cardiology.

Modulating brain’s stress circuity might prevent Alzheimer’s disease

Drug significantly prevented onset of cognitive and cellular effects in mice
November 17, 2015


Effect of drug treatment on AD mice in control group (left) or drug (right) on Ab plaque load. (credit: Cheng Zhang et al./Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association)

In a novel animal study design that mimicked human clinical trials, researchers at University of California, San Diego School of Medicine report that long-term treatment using a small-molecule drug that reduces activity of  the brain’s stress circuitry significantly reduces Alzheimer’s disease (AD) neuropathology and prevents onset of cognitive impairment in a mouse model of the neurodegenerative condition.

The findings are described in the current online issue of the journal Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.

Previous research has shown a link between the brain’s stress signaling pathways and AD. Specifically, the release of a stress-coping hormone called corticotropin-releasing factor (CRF), which is widely found in the brain and acts as a neurotransmitter/neuromodulator, is dysregulated in AD and is associated with impaired cognition and with detrimental changes in tau protein and increased production of amyloid-beta protein fragments that clump together and trigger the neurodegeneration characteristic of AD.

“Our work and that of our colleagues on stress and CRF have been mechanistically implicated in Alzheimer’s disease, but agents that impact CRF signaling have not been carefully tested for therapeutic efficacy or long-term safety in animal models,” said the study’s principal investigator and corresponding author Robert Rissman, PhD, assistant professor in the Department of Neurosciences and Biomarker Core Director for the Alzheimer’s Disease Cooperative Study (ADCS).

The researchers determined that modulating the mouse brain’s stress circuitry mitigated generation and accumulation of amyloid plaques widely attributed with causing neuronal damage and death. As a consequence, behavioral indicators of AD were prevented and cellular damage was reduced.  The mice began treatment at 30-days-old — before any pathological or cognitive signs of AD were present — and continued until six months of age.

One particular challenge, Rissman noted, is limiting exposure of the drug to the brain so that it does not impact the body’s ability to respond to stress. “This can be accomplished because one advantage of these types of small molecule drugs is that they readily cross the blood-brain barrier and actually prefer to act in the brain,” Rissman said.

“Rissman’s prior work demonstrated that CRF and its receptors are integrally involved in changes in another AD hallmark, tau phosphorylation,” said William Mobley, MD, PhD, chair of the Department of Neurosciences and interim co-director of the Alzheimer’s Disease Cooperative Study at UC San Diego. “This new study extends those original mechanistic findings to the amyloid pathway and preservation of cellular and synaptic connections.  Work like this is an excellent example of UC San Diego’s bench-to-bedside legacy, whereby we can quickly move our basic science findings into the clinic for testing,” said Mobley.

Rissman said R121919 was well-tolerated by AD mice (no significant adverse effects) and deemed safe, suggesting CRF-antagonism is a viable, disease-modifying therapy for AD. Drugs like R121919 were originally designed to treat generalized anxiety disorder, irritable bowel syndrome and other diseases, but failed to be effective in treating those disorders.

Rissman noted that repurposing R121919 for human use was likely not possible at this point. He and colleagues are collaborating with the Sanford Burnham Prebys Medical Discovery Institute to design new assays to discover the next generation of CRF receptor-1 antagonists for testing in early phase human safety trials.

“More work remains to be done, but this is the kind of basic research that is fundamental to ultimately finding a way to cure — or even prevent —Alzheimer’s disease,” said David Brenner, MD, vice chancellor, UC San Diego Health Sciences and dean of UC San Diego School of Medicine. “These findings by Dr. Rissman and his colleagues at UC San Diego and at collaborating institutions on the Mesa suggest we are on the cusp of creating truly effective therapies.”

Abstract of Corticotropin-releasing factor receptor-1 antagonism mitigates beta amyloid pathology and cognitive and synaptic deficits in a mouse model of Alzheimer’s disease

Introduction: Stress and corticotropin-releasing factor (CRF) have been implicated as mechanistically involved in Alzheimer’s disease (AD), but agents that impact CRF signaling have not been carefully tested for therapeutic efficacy or long-term safety in animal models.

Methods: To test whether antagonism of the type-1 corticotropin-releasing factor receptor (CRFR1) could be used as a disease-modifying treatment for AD, we used a preclinical prevention paradigm and treated 30-day-old AD transgenic mice with the small-molecule, CRFR1-selective antagonist, R121919, for 5 months, and examined AD pathologic and behavioral end points.

Results: R121919 significantly prevented the onset of cognitive impairment in female mice and reduced cellular and synaptic deficits and beta amyloid and C-terminal fragment-β levels in both genders. We observed no tolerability or toxicity issues in mice treated with R121919.

Discussion: CRFR1 antagonism presents a viable disease-modifying therapy for AD, recommending its advancement to early-phase human safety trials.

Allen Institute researchers decode patterns that make our brains human
Conserved gene patterning across human brains provide insights into health and disease
November 17, 2015


Percentage of known neuron-, astrocyte- and oligodendrocyte-enriched genes in 32 modules, ordered by proportion of neuron-enriched gene membership. (credit: Michael Hawrylycz et al./Nature Neuroscience)

Allen Institute researchers have identified a surprisingly small set of just 32 gene-expression patterns for all 20,000 genes across 132 functionally distinct human brain regions, and these patterns appear to be common to all individuals.

In research published this month in Nature Neuroscience, the researchers used data for six brains from the publicly available Allen Human Brain Atlas. They believe the study is important because it could provide a baseline from which deviations in individuals may be measured and associated with diseases, and could also provide key insights into the core of the genetic code that makes our brains distinctly human.

While many of these patterns were similar in human and mouse, many genes showed different patterns in human. Surprisingly, genes associated with neurons were most conserved (consistent) across species, while those for the supporting glial cells showed larger differences. The most highly stable genes (the genes that were most consistent across all brains) include those associated with diseases and disorders like autism and Alzheimer’s, and these genes include many existing drug targets.

These patterns provide insights into what makes the human brain distinct and raise new opportunities to target therapeutics for treating disease.

The researchers also found that the pattern of gene expression in cerebral cortex is correlated with “functional connectivity” as revealed by neuroimaging data from the Human Connectome Project.

“The human brain is phenomenally complex, so it is quite surprising that a small number of patterns can explain most of the gene variability across the brain,” says Christof Koch, Ph.D., President and Chief Scientific Officer at the Allen Institute for Brain Science. “There could easily have been thousands of patterns, or none at all. This gives us an exciting way to look further at the functional activity that underlies the uniquely human brain.”

Abstract of Canonical genetic signatures of the adult human brain

The structure and function of the human brain are highly stereotyped, implying a conserved molecular program responsible for its development, cellular structure and function. We applied a correlation-based metric called differential stability to assess reproducibility of gene expression patterning across 132 structures in six individual brains, revealing mesoscale genetic organization. The genes with the highest differential stability are highly biologically relevant, with enrichment for brain-related annotations, disease associations, drug targets and literature citations. Using genes with high differential stability, we identified 32 anatomically diverse and reproducible gene expression signatures, which represent distinct cell types, intracellular components and/or associations with neurodevelopmental and neurodegenerative disorders. Genes in neuron-associated compared to non-neuronal networks showed higher preservation between human and mouse; however, many diversely patterned genes displayed marked shifts in regulation between species. Finally, highly consistent transcriptional architecture in neocortex is correlated with resting state functional connectivity, suggesting a link between conserved gene expression and functionally relevant circuitry.

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Novel biomarkers for targeting cancer immunotherapy

Curator: Larry H. Bernstein, MD, FCAP



ABL has decades of experience working with human and animal samples to determine the efficacy, activity, and potency of vaccines and therapeutics. Our animal facility is located in close proximity to our laboratories allowing for fresh samples to be delivered in a timely manner for testing in ABL’s laboratories. ABL has a wealth of experience processing many different types of samples (blood, fluids, tissues, washes, etc) and viably freezing cells for shipment or testing at a later date.

In our continuing effort to ensure we are providing our clients with reliable and consistent data, ABL has worked with some of the top academic labs and experts in the country to cross validate our assays and sample collection techniques. This helps give our clients the assurance that the information they receive from ABL is accurate and can be used to make the significant decisions about their product candidates.

Our goal in providing a wide range of testing capabilities is to ensure the data accuracy to help our clients remove the risk associated with product development.


  • Determining absolute values and percentages of CD4 T-cells, CD8 T-cells, B cells, and NK cells from whole blood samples
  • Examine memory T-cell responses by FACS
  • NK functionality
  • Quantify secreted cytokines
  • ELISPOT: human, NHP, and murine samples
  • Intracellular cytokine staining
  • Luminex
  • FACS analysis to quantitate or determine production of cytokines, including IFN-gamma, TNF-alpha, IL-2, IL-4, IL-5, IL-6, and IL-10
  • Flex array system to target other cytokines/chemokines
  • Cytometric bead array
  • Lymphoproliferation assay

The state-of-the-art, non-toxic Immunotherapy protocols of the Issels® Immuno-Oncology Centers are designed to restore the body’s own complex immune and defense mechanisms to recognize and eliminate cancer cells.

They are always highly personalized and can be combined with gene-targeted or special standard cancer therapies according to individual needs.

The integrative Issels® Immuno-Oncology system is the result of extensive clinical and scientific research and has become internationally known for its remarkable rate of complete long-term remissions of advanced and standard therapy-resistant cancers.

Issels® Immuno-Oncology is based on and an expansion of the comprehensive strategy developed at the world’s first hospital specializing in the treatment of advanced and standard-therapy resistant cancers with 120 beds solely dedicated to immunotherapy based cancer treatment. Immunotherapy is now considered the most advanced of all cancer treatments.

Cytokines, NK Cells, LAK Cells, Stem Cells

Advanced Gene-Targeted Therapies

Cancer immunotherapy research is evolving to more targeted strategies

Discoveries in immune pathway research have helped refine cancer immunotherapy strategies to become more targeted.1,2





With the evolution to more targeted strategies, research is focusing on identifying predictors of individual immune response through specific tumor characteristics and factors in the tumor microenvironment, such as

  • The presence of tumor-infiltrating immune cells8
    • The ability of immune cells to infiltrate the tumor microenvironment may be a key criterion for a variety of immune-directed strategies, and could indicate which tumors are more likely to respond
  • Gene expression patterns in tumors, particularly the genes involved in immune response9
  • Cell surface protein expression
    • PD-L1 expression on tumor cells and tumor-infiltrating immune cells10,11
    • MUC1 expression on tumor cells12


  1. Chen DS, Mellman I. Oncology meets immunology: the cancer-immunity cycle. Immunity. 2013;39:1-10. PMID: 23890059
  2. Mellman I, Coukos G, Dranoff G. Cancer immunotherapy comes of age. Nature. 2011;480:480-489. PMID: 22193102
  3. Lesterhuis WJ, Haanen JB, Punt CJ. Cancer immunotherapy—revisited. Nat Rev Drug Discov. 2011;10:591-600. PMID: 21804596
  4. National Institutes of Health Accessed March 4, 2015.
  5. National Institutes of Health Accessed March 4, 2015.
  6. Glienke W, Esser R, Priesner C, et al. Advantages and applications of CAR-expressing natural killer cells. Front Pharmacol.2015;6:21. doi: 10.3389/fphar.2015.00021. PMID: 25729364
  7. National Institutes of Health Accessed March 4, 2015.
  8. Gajewski TF, Schreiber H, Fu YX. Innate and adaptive immune cells in the tumor microenvironment. Nat Immunol.2013;14:1014-1022. PMID: 24048123
  9. Ji RR, Chasalow SD, Wang L, et al. An immune-active tumor microenvironment favors clinical response to ipilimumab. Cancer Immunol Immunother. 2012;61:1019-1031. PMID: 22146893
  10. Taube JM, Anders RA, Young GD, et al. Colocalization of inflammatory response with B7-h1 expression in human melanocytic lesions supports an adaptive resistance mechanism of immune escape. Sci Transl Med. 2012;4:127ra37. PMID: 22461641  

 Cancer immunotherapy research: exploring the immune response against cancer

Cancer immunotherapy research seeks to understand how to utilize the body’s adaptive immune defense against cancer’s ability to evolve and evade destruction.1,2

The cancer immunity cycle characterizes the complex interactions between the immune system and cancer

The cancer immunity cycle describes a process of how one’s own immune system can protect the body against cancer. When performing optimally, the cycle is self-sustaining. With subsequent revolutions of the cycle, the breadth and depth of the immune response can be increased.1

Image of the cancer immunity cycle,featuring dendritic cells and active T cells, and how the immune system attacks cancer cells, leading to tumor apoptosis]


  • Oncogenesis leads to the expression of neoantigens that can be captured by dendritic cells
  • Dendritic cells can present antigens to T cells, priming and activating cytotoxic T cells to attack the cancer cells


  • Activated T cells travel to the tumor and infiltrate the tumor microenvironment


  • Activated T cells can recognize and kill target cancer cells
  • Dying cancer cells release additional cancer antigens, propagating the cancer immunity cycle

Tumors can evade immune destruction

By disrupting the processes of the cancer immunity cycle throughout the body, tumors can avoid detection by the immune system and limit the extent of immune destruction.1-3

Tumor microenvironment  –  Disrupting antigen detection


Lymph node – Inhibiting T-cell activation by dendritic cells

 Image of dendritic cell activating T cell, step 3 of cancer immunity cycle

Blood vessel   –    Blocking T-cell infiltration into tumor

 Image of T cell infiltrating tumor, step 5 of cancer immunity cycle

Tumor microenvironment –  Suppressing cytotoxic T-cell activity

Engaging the immune response: a unique approach to cancer management

Cancer immunotherapy strategies are designed to engage the immune system against tumors. This approach is unique in the oncology setting and introduces new considerations for cancer management.1,2

Tumors can evade immune destruction

By disrupting the processes of the cancer immunity cycle throughout the body, tumors can avoid detection by the immune system and limit the extent of immune destruction.1-3

tumor-microenv-sm Disrupting antigen detection

tumor-microenv-sm Disrupting antigen detection


Duration of response

The immune response has the ability to adapt with cancer as it evolves, and can become self-propagating once the cancer immunity cycle is initiated. Immune-directed strategies aim to leverage these attributes, with the goal of inducing a durable antitumor effect.3-5


Image showing T-cell infiltration into the tumor site can cause pseudoprogression]T-cell infiltration to the tumor site may cause an apparent increase in tumor size or the appearance of new lesions. This inflammatory effect can be misinterpreted as progressive disease, as it can be difficult to differentiate the different cell types in radiographic imaging. New criteria have been developed to better capture immune-related response patterns, and may guide evaluation of immunotherapies in clinical trials, and potentially in clinical care.1,2,6

Immune-related adverse events

While the goal of cancer immunotherapy research is to understand how to activate specific components of the immune response, the potential for off-target effects exists. Adverse event profiles may vary among different immune-directed strategies. As strategies grow more targeted, the recognition and management of immune-related adverse events will evolve.1,3

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Liposomal encapsulated drug

Writer and Curator: Larry H. Bernstein, MD, FCAP 

7.2  Liposomal encapsulated drug

7.2.1 Curcumin-containing liposomes stabilized by thin layers of chitosan derivatives

7.2.2 Colloids and Surfaces B: Biointerfaces 1 Sep 2013; 109:307–316

7.2.3 Increasing the stability of curcumin in serum with liposomes or hybrid drug-in-cyclodextrin-in-liposome systems

7.2.4 Influence of curcumin-loaded cationic liposome on anticancer activity for cervical cancer therapy

7.2.5 Liposome encapsulation of curcumin

7.2.6 Gemcitabine and γ-cyclodextrin-docetaxel inclusion complex-loaded liposome for highly effective combinational therapy of osteosarcoma

7.2.7 Self-organized thermo-responsive hydroxypropyl cellulose nanoparticles for curcumin delivery

7.2.8 The enhancement of gene silencing efficiency with chitosan-coated liposome formulations of siRNAs targeting HIF-1α and VEGF

7.2.9 Interactions of nanomaterials and biological systems. Implications to personalized nanomedicine

7.2.1 Curcumin-containing liposomes stabilized by thin layers of chitosan derivatives

Anna Karewicz, Dorota Bielska, Agnieszka Loboda, Barbara Gzyl-Malcher, Jan Bednar, Alicja Jozkowicz, Jozef Dulak, Maria Nowakowska


    • Cationic, hydrophobic and cationic–hydrophobic derivatives of chitosan were obtained and characterized.• Curcumin-containing liposomes were successfully stabilized by effective coating with these derivatives.• Liposomes coated with cationic–hydrophobic chitosan are most promising for curcumin delivery.• Such coated liposomes easily penetrate cell membrane and release curcumin in a controlled manner.• These curcumin-loaded liposomal systems are non-toxic for normal cells, but toxic for murine melanoma.


Stable vesicles for efficient curcumin encapsulation, delivery and controlled release have been obtained by coating of liposomes with thin layer of newly synthesized chitosan derivatives. Three different derivatives of chitosan were obtained and studied: the cationic (by introduction of the stable, quaternary ammonium groups), the hydrophobic (by attachment of N-dodecyl groups) and cationic–hydrophobic one (containing both quaternary ammonium and N-dodecyl groups). Zeta potential measurements confirmed effective coating of liposomes with all these chitosan derivatives. The liposomes coated with cationic–hydrophobic chitosan derivative are the most promising curcumin carriers; they can easily penetrate cell membrane and release curcumin in a controlled manner. Biological studies indicated that such systems are non-toxic for murine fibroblasts (NIH3T3) while toxic toward murine melanoma (B16F10) cell line.

Graphical abstract

Full-size image (30 K)

7.2.2 Colloids and Surfaces B: Biointerfaces 1 Sep 2013; 109:307–316


  • Cationic, hydrophobic and cationic–hydrophobic derivatives of chitosan were obtained and characterized.
  • Curcumin-containing liposomes were successfully stabilized by effective coating with these derivatives.
  • Liposomes coated with cationic–hydrophobic chitosan are most promising for curcumin delivery.
  • Such coated liposomes easily penetrate cell membrane and release curcumin in a controlled manner.
  • These curcumin-loaded liposomal systems are non-toxic for normal cells, but toxic for murine melanoma.


Stable vesicles for efficient curcumin encapsulation, delivery and controlled release have been obtained by coating of liposomes with thin layer of newly synthesized chitosan derivatives. Three different derivatives of chitosan were obtained and studied: the cationic (by introduction of the stable, quaternary ammonium groups), the hydrophobic (by attachment of N-dodecyl groups) and cationic–hydrophobic one (containing both quaternary ammonium and N-dodecyl groups). Zeta potential measurements confirmed effective coating of liposomes with all these chitosan derivatives. The liposomes coated with cationic–hydrophobic chitosan derivative are the most promising curcumin carriers; they can easily penetrate cell membrane and release curcumin in a controlled manner. Biological studies indicated that such systems are non-toxic for murine fibroblasts (NIH3T3) while toxic toward murine melanoma (B16F10) cell line.

7.2.3 Increasing the stability of curcumin in serum with liposomes or hybrid drug-in-cyclodextrin-in-liposome systems

Matloob AH1Mourtas S1Klepetsanis P2Antimisiaris SG3.
Int J Pharm. 2014 Dec 10; 476(1-2):108-15

Curcumin (CURC) was incorporated in liposomes as free drug or after formation of hydropropyl-β- or hydroxypropyl-γ-cyclodextrin (HPβCD or HPγCD) complexes prepared by coprecipitation and characterized by X-ray diffractometry. Liposomes encapsulating CURC as free drug or CD-complexes (hybrid formulations) were prepared by the dehydration-rehydration vesicle (DRV) method followed by extrusion, and characterized for size, zeta-potential and CURC loading. CURC stability (at 0.01 and 0.05mg/mL) in 80% (v/v) fetal bovine serum (FBS) was evaluated at 37°C. Results demonstrate that HPβCD stabilizes CURC more than HPγCD, but liposome encapsulation provides substantially more protection, than CDs. CURC stabilization is similar, when encapsulated as free compound or CD-complex. However, the last method increases CURC loading by 23 times (depending on the lipid composition of liposomes and the CD used), resulting in higher solubility. The stability profile of CURC in serum depends on the composition of liposomes and CURC concentration, since at lower concentrations larger CURC fractions are protected due to protein binding. Compared to the corresponding CD complexes, hybrid formulations provide intermediate CURC solubility (comparable to HPβCD) but profoundly higher stabilization.

7.2.4 Influence of curcumin-loaded cationic liposome on anticancer activity for cervical cancer therapy

Saengkrit N1Saesoo S1Srinuanchai W1Phunpee S1Ruktanonchai UR2.
Colloids Surf B Biointerfaces. 2014 Feb 1; 114:349-56.


  • The delivery of curcumin using liposomes was explored in cervical cancer cell lines.
  • A critical role of DDAB in liposomes containing curcumin was investigated.
  • DDAB is a potent inducer of cell uptake, anticancer efficiency and cell death.
  • Anticancer efficiency of liposomal curcumin was more pronounced than free curcumin.

The delivery of curcumin has been explored in the form of liposomal nanoparticles to treat various cancer cells. Since curcumin is water insoluble and an effective delivery route is through encapsulation in liposomes, which were modified with three components of DDAB, cholesterol and non-ionic surfactant. The purpose of this study was to establish a critical role of DDAB in liposomes containing curcumin at cellular response against two types of cell lines (HeLa and SiHa). Here, we demonstrate that DDAB is a potent inducer of cell uptake and cell death in both cell lines. The enhanced cell uptake was found on DDAB-containing liposome, but not on DDAB-free liposome. However, the cytotoxicity of DDAB-containing liposomes was high and needs to be optimized. The cytotoxicity of liposomal curcumin was more pronounced than free curcumin in both cells, suggesting the benefits of using nanocarrier. In addition, the anticancer efficiency and apoptosis effect of the liposomal curcumin formulations with DDAB was higher than those of DDAB-free liposomes. Therefore curcumin loaded liposomes indicate significant potential as delivery vehicles for the treatment of cervical cancers.

Full-size image (19 K)

7.2.5 Liposome encapsulation of curcumin: physico-chemical characterizations and effects on MCF7 cancer cell proliferation.

Hasan M1Belhaj N1Benachour H2Barberi-Heyob M3Kahn CJ4Jabbari E5Linder M1Arab-Tehrany E6.
Int J Pharm. 2014 Jan 30; 461(1-2):519-28

The role of curcumin (diferuloylmethane), for cancer treatment has been an area of growing interest. However, due to its low absorption, the poor bioavailability of curcumin limits its clinical use. In this study, we reported an approach of encapsulation a curcumin by nanoliposome to achieve an improved bioavailability of a poorly absorbed hydrophobic compound. We demonstrated that liposomal preparations to deliver curcumin increase its bioavailability. Liposomes composed of salmon’s lecithin also improved curcumin bioavailability compared to those constituted of rapeseed and soya lecithins. A real-time label-free cell analysis system based on real-time cell impedance monitoring was used to investigate the in vitro cytotoxicity of liposomal preparations.

Fig. 1. Chemical structure of curcuminoids (curcumin, demethoxycurcumin, bis

Table 2 Membrane fluidity of nanoliposomes with and without curcumin.
Sample                                            Membrane fluidity
Salmon liposome                           3.19 ± 0.08a,b,*
Curcumin loaded
salmon liposome                           2.81 ± 0.05*
Rapeseed liposome                       3.53 ± 0.07a,*
Curcumin loaded
rapeseed liposome                        2.83 ± 0.04*
Soya liposome                                3.58 ± 0.10b,*
Curcumin loaded
soya liposome                                2.83 ± 0.02*
* Significant t-test                         (p < 0.05)
between salmon
and rapeseed
(a), salmon and soya
(b), curcumin loaded liposome
and liposome of the same lecithin.

Fig. 3. Transmission electron microscopic images of rapeseed
(a), soya
(b) and salmon
(c) nanoliposomes

Fig. 4. Cell index (CI) kinetics of the MCF-7 cells exposed to different concentrations of curcumin.
CI was monitored during 72 h after compounds exposure. Reported data are the means of three replicates.
Statistical differences were found after 24 h for 12 and 20 mM of curcumin vs. control cells (without curcumin)
and between 12 mM and 20 mM of curcumin.

7.2.6 Gemcitabine and γ-cyclodextrin-docetaxel inclusion complex-loaded liposome for highly effective combinational therapy of osteosarcoma

Int J Pharm. 2014 Nov 26; 478(1):308-317.

Fig.1. Schematic illustration of DTX and GEM loaded nanocarriers. First, DTX was complexed with HP-g-cyclodextrin to form a DTX/CD inclusion complex.
In the second step, GEM and DTX/CD complex was incorporated in a PEGylated liposome.

In vitro release study
The release study of DTX/GEM-L was performed in phosphate buffered saline (pH 7.4) at 37C. As shown in Fig. 3, no initial burst release phenomenon was
observed with both the drugs indicating that none of the drugs were present in the surface of liposome. As expected, hydrophilic GEM released faster than
that of DTX. 50% of GEM released within 16 h of study period and almost 90% of drug released during the 48 h study period. The faster release of drug was
attributed to the free diffusion of drug from the core of liposomes to the release media. On the other hand, DTX relatively released slowly from the liposome
system. It could be due to the presence of inclusion complex which delayed the release rate of DTX. Nearly 40% of DTX released from the CD/liposome
system at the end of 48 h study period. For this system, various factors decide the drug release patterns including nature of drug, interaction between drug
and lipid, diffusion path length. Moreover, difference in the hydrophobicity of drugs decides the drug release pattern. GEM is a highly hydrophilic drug
while DTX is a hydrophobic drug.

Cytotoxic effect of GEM and DTX against MG63 cancer cells
The in vitro antitumor potential of GEM and DTX (individually and combined) was evaluated in MG63 bone tumor cells. The cells were exposed to increasing
concentration of single as well as combined drug in a time-dependent manner. As shown in Fig. 4, both DTX and GEM inhibited the growth of the cancer cell
in a dose-dependent and time-dependent manner. As seen, DTX was more effective in controlling the cell growth rate compared to that of GEM. However,
combined DTX/GEM showed better antitumor potential than that of individual drugs. Most importantly, DTX/GEM-L showed a more pronounced tumor inhibiting
effect than the free drug combination. For example, at a fixed concentration of 1 mg/mL, free DTX/GEM showed 55% cell viability compared to 40% cell viability
for DTX/GEM-L at the end of 24 h. Notably, cellular viabilities of combinational drug were significantly lower than that of individual GEM or DTX. IC50 value
was calculated to quantitatively estimate the inhibitory levels. The IC50 for free GEM and free DTX were >10 mg/mL and 5.4 mg/mL.

Fig. 2. Transmission electron microscope (TEM) image of nanocarriers (A) blank liposome (B) DTX/GEM-loaded CD/liposome.

Fig. 3. In vitro release kinetics of DTX and GEM from DTX/GEM-L. The release study was performed in phosphate buffered saline (pH 7.4) at 37C. The nanoparticle
dispersions were kept in dialysis tube placed in tube containing media. The release samples were collected at predetermined time intervals. *p < 0.05 is the
statistical difference between release rate of GEM and DTX.

Fig. 4. In vitro cytotoxicity evaluation of formulations on MG63 cancer cells. The cells were treated with DTX, GEM, DTX/GEM, and DTX/GEM-L and incubated
for 24 h (a) and 48 h (b), respectively. Untreated cells were considered as control. (c) Cytotoxicity of blank nanoparticles. The free DTX and free GEM was
treated in respective concentrations while a molar ratio of 1:1 (two drugs) was used for DTX/GEM combinational cocktail as well as nanocarriers. *p < 0.05
and **p < 0.01 are the statistical difference between cytotoxicity of DTX/GEM-L and free GEM/DTX.

7.2.7 Self-organized thermo-responsive hydroxypropyl cellulose nanoparticles for curcumin delivery

European Polymer Journal Sep 2013; 49(9)9:2485–2494

A tunable temperature-responsive nanoparticulate system based on the ionic modifications of hydroxypropyl cellulose (HPC) was obtained. Two derivatives of HPC were successfully obtained and characterized: cationic (modified with trimethylammonium groups) and anionic (modified with styrenesulfonate groups). Due to the polycation-polyanion interactions they spontaneously self-assemble into nanoparticles in water. The size and surface charge of the nanoparticles can be controlled by the polycation/polyanion ratio. The resulting structures are spherical with diameters in the range from 150 to 250 nm, as confirmed by AFM, SEM, and DLS measurements. The size of the nanospheres increases in elevated temperatures. A model compound, curcumin, known for its anti-cancer and anti-inflammatory properties, was effectively entrapped inside nanospheres. Its release profile was found to be temperature-dependent.

Graphical abstract

Full-size image (10 K)


► Cationic and anionic derivatives of hydroxypropyl cellulose were synthesized. ► The polymers self-assemble forming spherical nanoparticles. ► The size of the nanoparticles is temperature-dependent. ► Curcumin could be efficiently entrapped within the nanospheres. ► No burst effect was observed for curcumin release.

7.2.8 The enhancement of gene silencing efficiency with chitosan-coated liposome formulations of siRNAs targeting HIF-1α and VEGF

Int J Pharm. 2014 Nov 13; 478(1):147-154.

RNA interference (RNAi) holds considerable promise as a novel therapeutic strategy in the silencing of disease-causing genes. The development of effective delivery systems is important for the use of small interfering RNA (siRNA) as therapy. In the present study, we investigated the effect on breast cancer cell lines and the co-delivery of liposomes containing siHIF1-α and siVEGF. In order to achieve the co-delivery of siHIF1-α and siVEGF and to obtain lower cytotoxicity, higher transfection and silencing efficiency, in this study, we used chitosan-coated liposomal formulation as the siRNA delivery system. The obtained particle size and zeta potential values show that the chitosan coating process is an effective parameter for particle size and the zeta potential of liposomes. The liposome formulations loaded with siHIF1-α and siVEGF showed good stability and protected siRNA from serum degradation after 24-h of incubation. The expression level of VEGF mRNA was markedly suppressed in MCF-7 and MDA-MB435 cells transfected with chitosan-coated liposomes containing HIF1-α and VEGF siRNA, respectively (95% and 94%). In vitro co-delivery of siVEGF and siHIF1-α using chitosan-coated liposome significantly inhibited VEGF (89%) and the HIF1-α (62%) protein expression when compared to other liposome formulations in the MDA-MB435 cell. The co-delivery of siVEGF and siHIF1-α was greatly enhanced in the vitro gene silencing efficiency. In addition, chitosan-coated liposomes showed 96% cell viability. Considering the role of VEGF and HIF1-α in breast cancer, siRNA-based therapies with chitosan coated liposomes may have some promises in cancer therapy.

Fig. 2. TEM photographs of  cationic (a) and chitosan-coated (b) liposomes.

As shown in Table 1, the particle sizes of the liposome formulations fluctuated from 131.25 2.76 nm to 641.75 + 5.24 nm. The particle size of the chitosan-coated liposomes was significantly larger
than the non-coated liposome formulations (between 510.65 + 49.71 nm and 641.75 + 25.24 nm). In addition, the particle sizes of the liposome formulations containing siVEGF and siHIF were
smaller than those containing either siVEGF or siHIF  only (Table 1). According to the net surface charge values, the prepared liposome formulations which are suitable for the methods used,
are determined to have the expected electrical charge type (anionic liposome 23.10 + 0.71 mV; cationic liposome 39.05  1.63 mV). It was determined that siRNA which was added to the
formulation and coating with the chitosan of  the liposomes affected their net surface charge. The surface charge values changed into negative directions with the amount of siRNA added
to the formulation (anionic liposome 26.60 + 0.14 mV; cationic liposome 29.95 + 0.64 mV). It was determined that the surface charge values changed into positive directions during the
coating process of the negatively charged liposomes with a natural cationic polymer chitosan (chitosan coated anionic liposome 27.0 + 0.57). These  data suggest the liposome exerts
a protective effect on the siRNA.

7.2.9 Interactions of nanomaterials and biological systems. Implications to personalized nanomedicine

Adv Drug Deliv Rev. 2012 Oct; 64(13):1363-84.

The application of nanotechnology to personalized medicine provides an unprecedented opportunity to improve the treatment of many diseases. Nanomaterials offer several advantages as therapeutic and diagnostic tools due to design flexibility, small sizes, large surface-to-volume ratio, and ease of surface modification with multivalent ligands to increase avidity for target molecules. Nanomaterials can be engineered to interact with specific biological components, allowing them to benefit from the insights provided by personalized medicine techniques. To tailor these interactions, a comprehensive knowledge of how nanomaterials interact with biological systems is critical. Herein, we discuss how the interactions of nanomaterials with biological systems can guide their design for diagnostic, imaging and drug delivery purposes. A general overview of nanomaterials under investigation is provided with an emphasis on systems that have reached clinical trials. Finally, considerations for the development of personalized nanomedicines are summarized such as the potential toxicity, scientific and technical challenges in fabricating them, and regulatory and ethical issues raised by the utilization of nanomaterials.

The application of nanotechnology to medicine has created an interdisciplinary research field, often referred to as nanomedicine, which has the potential to significantly improve the way many diseases are treated [1]. Within the nascent but rapidly growing field of nanomedicine, personalized medicine applications are among the most promising and exciting innovations [2]. Personalized medicine consists of a healthcare strategy where specific therapeutics are prescribed to patients on the basis of genetic, phenotypic, and environmental factors that influence the response to therapy [3]. It has long been recognized that individual patients respond differently to the same drug in terms of efficacy and safety due to the complexity and heterogeneity of diseases and patients [4]. For example, some drugs and dosages cause adverse health effects within a particular patient population while a different patient population responds well to the drug treatment with minimal side effects. Similarly, there may be marked variability in efficacy as well. With an increased understanding of genomics and the emergence of novel technologies for the investigation of molecular profiling and genetic mapping of a patient, personalized medicine is poised to begin reaching its full potential.

The application of nanomaterials to medical problems has already demonstrated a clinical impact in terms of delivery strategies for a range of bioactive molecules, including therapeutic agents, nucleic acids and imaging contrast agents [5]. Nanotechnology enables a combinatorial library of nanoparticles to be synthesized with precise control over surface modifications (e.g., targeting moieties, charge modification, stealth), size, shape, and other particle characteristics that can be screened in order to find the best particle properties for patient-specific therapeutics [6]. There are already examples of nanomedicine in the clinic. Doxil®, a PEGylated liposomal doxorubicin formulation, was the first nanosized therapeutic on the market in 1995 and was used as an effective treatment for metastatic breast cancer and recurrent ovarian cancer [7]. Other systems are in various stages of preclinical and clinical advancements. For example, a targeted therapeutic nanoparticle, named BIND-014, that accumulates in tumors while avoiding uptake by the healthy cells have shown promising results in an ongoing clinical trial [6]. Another example is a lipid nanoparticulate delivery system (Oncoprex®) containing plasmid DNA encoding the TUSC2 tumor suppressor that is being studied in combination with erlotinib, a human epidermal growth factor receptor (EGFR) inhibitor, in lung cancer patients unresponsive to erlotinib or lacking the EGFR mutation [8]. Preclinical studies in animals showed that intravenous TUSC2 nanoparticles work synergistically with erlotinib to overcome drug-induced resistance by simultaneously inactivating the EGFR pathway and by inducing apoptosis in resistant cells. A phase II clinical trial evaluating intravenous TUSC2 nanoparticles in combination with erlotinib will begin in 2012. This will provide two possible therapeutic options depending on the tumor EGFR expression: EGFR inhibitor monotherapy or in combination with the nanoparticles. Progress has also been made in the development of versatile nanocarriers placing emphasis upon patient-specific treatments. For example, Zhang and colleagues recently proposed red blood cell (RBC) membrane-coated nanoparticles to evade the immune system and exhibit longer retention time in the blood [9]. This approach suggests an elegant yet hard to clinically-implement methodology: the patient’s RBCs are collected and emptied to leave only the membranes, the latter are then fused with pre-formed polymeric nanoparticles. The resultant RBC-membrane coated nanoparticles are therefore decorated with the patient’s own proteins and cell membranes to evade the host’s defense mechanisms.

While personalized medicine can guide the design and use of nanocarriers, nanotechnology can also aid in the collection of genomic and molecular data necessary for personalized medicine. Advances in personalized medicine occur through the development of novel nanomaterials as well as technologies for the early detection, imaging, and identification of molecular signatures of diseases. The field of pharmacogenetics and “omics” technologies (e.g., pharmacogenomics, pharmacoproteomics and pharmacometabonomics) have enabled the investigation of an individual patient’s genetic and molecular profiles. This information have provided insights into the mechanisms of disease and how to appropriately combine therapeutics with specific disease profiles. Nanoscale materials and technologies have the ability to greatly expand the molecular and genetic information gathered from patients. For example, the GeneChip® microarray allows nanoscale patterning of biological molecules on surfaces with exquisite control over their spatial placement to obtain DNA sequencing [1, 10]. With the ability to control molecular deposition now in the nanometer range, a million-fold increase in information density could be packed in “nanoarrays” for the detection of nucleic acids or proteomic profiles [1113]. Another example is gold nanoparticles modified with biorecognition molecules that are used for high-throughput genomic detection and are currently approved for use by the FDA [1416].

A research report of commercialization efforts of nanomedicine from the Business Communications Company indicated that the global nanomedicine sales are projected to grow to over $100 billion by 2014 [17]. There are increasingly growing partnerships between biopharmaceutical companies and nanomedicine startups pursuing nanomedicine R&D projects due to the enormous potential applications of nanotechnology to healthcare. One of the predominant focuses is drug delivery applications. The other nanomedicine products include in vivo imaging agents, in vitro diagnostics, biomaterials, and active implants [18]. As our fundamental understanding of diseases increases, implementations of nanotechnology will offer an expanding toolbox to improve point-of-care diagnostics, enable integration of diagnostics with therapeutics, and treat patients with a more personal approach.

While nanomedicine starts to show much promise to the field of personalized medicine, further research is required to expand its impact. In particular, a fundamental understanding of the interactions between nanomaterial surfaces and complex proteins in biological fluids needs to be achieved. This would influence both in vivo delivery of therapeutics and ex vivo diagnostics. Likewise, interactions between nanomaterials and cells, through non-specific contacts or ligand-receptor interactions, as well as the intracellular mechanisms responsible for trafficking of a nanomaterial in the cell, must be more thoroughly characterized. There is a complex relationship between a nanomaterial’s physicochemical properties (e.g., size, charge, surface properties), and its interaction within a biological system. Small changes in size, charge, surface functionalization and chemical composition can lead to radically different interactions with living systems [19]. These interactions then determine the biocompatibility, stability, biological performance and side effects of the nanomaterial. In this regard, understanding the nano-bio interactions and the relationships between the nanomaterial properties/structure and activity will provide a conceptual basis for the rational design and safe use of personalized nanomedicines.

In the first section of this review, we will address different areas in which better comprehension is required and propose examples showing how nanomaterials interact with their environment in complex and subtle manners. Each subject will be discussed from the perspective of its implications for personalized medicine. The second section will highlight some examples that demonstrate current trends and novel concepts in the field of nanomedicine and its impact on personalized medicine. These include nano-sized platforms for the targeted delivery of therapeutics, contrast agents for diagnostic imaging, and theranostic nanoparticles. The use of nanoparticles for the discovery of biomarkers and molecular diagnostic will also be evaluated. Finally, the third section will present the scientific and technical challenges associated with developing personalized nanomedicines, various safety, political and ethical issues raised in the field, as well as the obstacles and limitations associated with personalized nanomedicine.

Interactions of nanomaterials in biological systems

As the role of nanomaterials in biology and medicine continues to grow, the number of situations in which they will be in contact with biological systems will indisputably increase. In this domain where the complexities of nanotechnology and human physiology combine, fundamental understanding is essential before one can think about intricate applications. In the following section, three different aspects of the interactions between nanomaterials and proteins will be presented. Their relevance to personalized medicine will be highlighted in the last section.


When nanoparticles are utilized for treatment, imaging a tumor, or aiding to establish a diagnosis upon systemic administration, the first tissue they encounter is the blood and all the proteins it contains within. Similarly, when diagnostic nanomaterials are used in vitro or ex vivo to analyze samples of biological fluids, they will come in contact with complex proteins mixtures. The adsorption of proteins on a substrate is a much more complex phenomenon when the surface possesses nanoscale dimensions as compared to that of larger proportions [20]. The relative surface area of nanomaterials is very large and their features are on the same order as proteins (1 to 20 nm) [21]. The interactions between proteins and materials of the nano- and meso- or macroscales are therefore both quantitatively and qualitatively different.

Upon contact with biological fluids (e.g., blood, interstitial fluid or mucosal secretions), nanoparticles are coated with proteins that may change their surface charge and properties. This biological coating can subsequently lead to the loss of performance due to an increase in hydrodynamic size or aggregation. The protein that binds most strongly to polymeric nanoparticles, liposomes, iron oxide nanoparticles and carbon nanotubes are albumin, immunoglobulins, fibrinogen, apolipoproteins and proteins from the complement cascade [20].

Decreasing the nonspecific protein interaction

When nanoparticles are administered systemically, the proteins that adhere to their surface will greatly affect their circulation and biodistribution [22, 23]. Complement and immunoglobulin binding promotes particle opsonization, leading to recognition by the mononuclear phagocyte system (MPS) and rapid clearance from the bloodstream [22]. MPS capture is dictated by macrophage phagocytosis (mostly in the sinusoids of the liver) and splenic filtration [23, 24]. Aggregation of nanoparticles in the blood can also lead to retention and embolism in the lung capillaries [25].

Short circulation half-life, low efficacy, and toxicity caused by accumulation of foreign materials in the liver and spleen are the primary limitation for the systemic administration of nanoparticles. These issues have led to the development of strategies aimed at increasing blood residence time. Among these, the use of poly(ethylene glycol) (PEG) for surface functionalization has been shown to dramatically reduce protein absorption, particularly apolipoprotein J and complement protein C3, through hydrophilicity and steric repulsion effects, therefore extending residence time in blood [2628]. This has allowed the “stealth” nanoparticle carriers to be present in the bloodstream long enough to reach or recognize their therapeutic site of action [29].

Examples of “stealth” nanocarriers include PEGylated liposomal doxorubicin (Doxil®) and the PLA-PEG micelle form of paclitaxel (Genexol-PM®, marketed in Korea in 2007). Encapsulating doxorubicin within PEGylated nanoparticles allows for extended circulation half-life in blood and higher tumor concentration of doxorubicin. The homing to the disease site is driven only by the particles’ nano-dimensions and PEGylated surface through the enhanced permeability and retention (EPR) effect [30], which results from enhanced vascular permeability and the absence of a functioning lymphatic system, and is not related to any specific recognition of the target.

In addition to causing quick clearance, nonspecific interactions of nanomaterials with proteins from complex biological samples (e.g., human blood serum, plasma and tissue extracts) hamper the full exploitation of ex vivo nano-based diagnostics and arrays [31]. Novel diagnostic nanomaterials are emerging for the detection and quantification of less abundant biomarkers in biological samples and are envisioned to provide ground-breaking tools for personalized nanomedicine [32]. These nanoparticles and nanostructures possess many unique and advantageous physical properties when applied as ultra-sensitive signal transducers and protein biosensors in the fields of molecular diagnostics and proteomics. Their nanoscale dimensions also result in increases in information quality, quantity and density. Major examples include nanocantilevers, nanowires, nanotube arrays and oligonucleotide-modified gold nanoparticle-based bio-barcode assays that enable multi-biomarker detection [1]. However, the development of these approaches with high sensitivity and selectivity faces several bottlenecks including deconvolution of noise from the signal, especially in regard to biofouling. For the analysis of proteomic signatures, a major challenge will be the identification of signatures from low-concentration molecular species, in the presence of extremely high concentrations of non-specific serum proteins. Nonspecific binding remains a major concern which may lead to false positive signals and low signal-to-noise ratios for a given assay. For various applications such as affinity biosensors or nanoarrays, it is critical to block possible sites for nonspecific binding and/or treat nanomaterials with surface coatings that combine an ultralow fouling background with abundant biorecognition elements. To solve this problem, nonfouling coating materials such as zwitterionic polymers, PEG and its derivates have been developed to prevent nonspecific protein adsorption when exposed to complex media [33, 34]. For example, combined with a surface plasma resonance (SPR) sensor, the protein arrays created using zwitterionic poly(carboxybetaine acrylamide) are able to detect specific cancer biomarkers and monitor the kinetics of antigen-antibody interactions from 100% human blood plasma with high specificity and sensitivity [33]. The background noise was very low due to significantly minimized total nonspecific protein adsorption on the functionalized zwitterionic surface.

Limiting the immunogenicity

Decreasing the immunogenicity of a nanomaterial is also of critical importance since therapeutic nanoconstructs have dimensions very similar to those of pathogens for which recognition signals were positively selected for evolution [35]. The understanding of the immune reactions to therapeutic and diagnostic nanomaterials is still poorly characterized and additional knowledge is required to ensure which characteristics warrant repeated systemic administration without adverse reactions.

For example, in preclinical studies, the phenomenon aptly named accelerated blood clearance (ABC) has been observed in animal models for various types of nanoconstructs [3638]. In this effect, an initial sensitization of the animals to the nanomaterial triggers a transient immune response and induction of Immunoglobulin M (IgM) antibody which prompts rapid clearance of the subsequently administered doses by increased capture in the liver and the spleen [1214]. The factors that impact the appearance of this phenomenon are multifaceted and include the nature of the payload of the nanomaterial [39, 40], the dose administered [3941], and other physicochemical characteristics of each nanoconstruct [41, 42]. The encapsulation of cytotoxic compounds seems to highly diminish the ABC effect, possibly through a deleterious effect on the B cells responsible for the secretion of IgM [39, 40]. In the current context where all nanomedicines on the market contain anticancer drugs, the manifestations of ABC have had limited significance. However, the future development of nanomedicines for all types of diseases and encapsulating a variety of drugs will certainly have to address that problem before nanomaterials can be repeatedly and consistently administered.

Understanding nanomaterial-protein interactions is also important for the development of safer and better tolerated nanomedicine. PEGylated liposomes are known to exhibit prolonged circulation time in blood and have had success in translation to the clinic. However, infusion of therapeutic liposomal drugs such as Doxil® as well as other amphiphilic lipids which have reached the bedside (e.g., Cremophor EL®) could lead to a hypersensitivity syndrome called complement activation-related pseudoallergy (CARPA). The CARPA syndrome differs from anaphylaxis since it does not involve IgE but arises as a consequence of activation of the complement (C) system. Also, CARPA improves upon subsequent exposure and can be mitigated in patients by reducing the infusion rate as opposed to anaphylaxis where re-exposition usually triggers a more serious reaction [43].

Moghimi et al. have demonstrated that liposomes prepared using anionic phospholipid-PEG conjugates caused CARPA, partly because the highly cationic region of the globular C1q protein binds with the anionic charge localized on the phosphate oxygen of the lipid-PEG conjugate through electrostatic interaction. This induces activation of the complement cascade, opsonization of the nanoparticle surface and anaphylatoxin production (reflected in significant rises in SC5b-9, C4d, C3a and C5a levels in human sera) [44]. CARPA is mostly mild and transient, but in some patients, it can be severe or even lethal. In addition, a main manifestation of complement activation is cardiopulmonary distress; therefore, CARPA may be a safety issue primarily in cardiac patients.

Several methods have been explored to circumvent the problem. A previous study revealed that removal of the negative charge by methylation of the phosphate oxygen of lipid-PEG conjugates totally prevented complement activation. Others have recently synthesized a range of neutral lipopolymers and variations thereof for liposome engineering [45]. Remarkably, preliminary investigations have demonstrated that such lipopolymer-incorporated liposomes are poor activators of the human and porcine complement system when compared to vehicles bearing anionic lipid-PEG conjugates [46]. The nanoformulations prepared with neutral lipopolymers may hold great potential to treat patients with severe CARPA response or cardiac disease. More studies have been conducted to test the CARPA concept and the immunological interactions of liposomal and amphiphilic polymeric nanoparticles [47, 48]. In addition to the CARPA reactions observed in the clinics, complement activation also leads to opsonisation of the nanomaterials and enhances their clearance by the MPS. Therefore, any measure to prevent its activation could translate into increased circulation times and efficiency. Figure 1 demonstrates the different pathways that trigger the complement system and how physicochemical properties of nanomaterials can switch the activation process from one pathway to another [4955].

pathways of complement cascade activation nihms-401532-f0001

pathways of complement cascade activation nihms-401532-f0001

The physicochemical properties of the nanomaterial surface can trigger the different pathways of complement cascade activation [4955]. The classical pathway is activated through deposition of specific proteins like antibodies and others. The lectin pathway is triggered by the recognition of the surface by a Mannose-binding Lectin (MBL) through pathogen-associated motifs. The lectin subsequently interacts with a serine protease (MASP) to elicit the formation of a C3-convertase (C4b2a) analogously to the classical pathway. The spontaneous tickover responsible for the alternative pathway activation is constantly present in plasma. When not properly regulated, the preferred deposition of the C3b products on the surface of the nanomaterial amplifies the cascade activation. All 3 pathways lead to C5-convertases that cleave C5 and lead to the deposition of the terminal membrane attack complex which can lyse pathogens and senescent cells, further releasing proinflammatory mediators. The release of proinflammatory chemoattractants is symbolized by the yellow outburst.

Exploiting the beneficial aspects of protein-binding

The nanomaterial-protein interactions should not only be viewed as being disadvantageous, as some preferential interactions can be used to guide the distribution of nanoparticles to specific tissues. For example, decoration of nanomaterial with specific proteins prior to injection has been exploited for particular targeting purposes [5658].

More recently, a possibly higher response rate in a subset of patients observed during the first clinical studies on albumin-coated paclitaxel (nab-PTX, Abraxane®) sparked a flash of enthusiasm in the drug delivery community. In this study, it was found that different response rates between individual patients receivingnab-PTX could be explained by degrees of expression in the extratumoral protein SPARC (secreted protein acidic and rich in cysteine) [59]. SPARC is a secreted matricellular glycoprotein with high binding affinity to albumin which functions to regulate cell-matrix interactions [60]. Its overexpression is associated with increased tumor invasion and metastasis, leading to poor prognosis in multiple tumor types including breast, prostate, and head and neck cancers [61]. In this context, the prospect that SPARC-positive patients would respond better to nab-PTX was particularly appealing.

Desai et al. tested this hypothesis by correlating the clinical response and SPARC tumor expression in a retrospective analysis of 60 patients receiving nab-PTX as monotherapy against head and neck cancer [59]. It was found that response to nab-PTX was higher for SPARC-positive patients (83%) than SPARC-negative patients (25%). As shown in Figure 2, a possible explanation for the positive correlations between SPARC expression and the drug is that the interactions of albumin and SPARC in the tumor interstitium could facilitate the accumulation of nab-PTX in the tumor. Furthermore, the albumin-drug interactions were thought to facilitate the transport of paclitaxel molecules across endothelial barriers via gp60 receptor and caveolin-1 mediated transcytosis [59].

Mechanisms for the transport and accumulation of albumin-bound paclitaxel in tumor nihms-401532-f0002

Mechanisms for the transport and accumulation of albumin-bound paclitaxel in tumor nihms-401532-f0002

Mechanisms for the transport and accumulation of albumin-bound paclitaxel in tumors. Binding of albumin-bound paclitaxel complexes to the gp60 receptor and subsequent caveolin-1 mediated transcytosis results in transport across the endothelial barrier of the tumor vasculature. SPARC, an albumin-binding protein present in the tumor interstitium, enhances accumulation of the complexes in tumor tissue. Figure taken from reference [59].

As further supporting evidence, a study in animals with multiple tumor xenografts also showed correlations between the relative efficacy of nab-PTX and SPARC expression. In this study, the albumin-containing formulation was compared to polysorbate-based docetaxel. In comparison with control groups, the effect ofnab-PTX in HER2-positive breast tumors with increasing SPARC expression seemed superior to that witnessed in MDA-MB-231/HER2-positive tumors with low SPARC expression [62]. It should be noted, however, that differences between the pharmacological agents used (paclitaxel vs. docetaxel) and the large discrepancies between the doses of drug administered in the different groups strongly limit the conclusions that can be drawn from this study.

To complicate matters, a recent study yielded confounding evidence about the implication of SPARC on the efficacy of nab-PTX. In animals bearing patient-derived non-small cell lung cancer (NSCLC) tumor xenografts, the response to nab-PTX could not be correlated to SPARC expression. In this study, the improved antitumor effect of the albumin-based formulation over solvent-solubilized PTX could also be observed in some SPARC-negative tumors and the induction of SPARC expression in low-responsive tumors could not enhance activity [63]. This implies the possibility of other mechanisms being implicated to explain the response to nab-PTX. In this study, the compared doses of drugs (30 mg/kg/day of nab-PTX vs. 13.4 mg/kg/day of solvent-formulated PTX) were reputedly equitoxic. However, these doses were ascertained based on the tolerability of the compound in mice [64]. Hence, it still remains difficult to address if the benefits of nab-PTX over solvent-formulated PTX are uniquely owed to improved tolerability or to real targeting manifestations.

In conclusion, more efforts are needed before we can ascertain the role of SPARC expression as a biomarker for personalized anticancer therapies using albumin-based formulations. For one, there is a current lack of understanding of the stability of the 130-nm albumin-encapsulated PTX nanoparticles once it is introduced in the blood. Some reports mention that, upon dilution, the nanoparticles dissolve into individual albumin-PTX complexes [65], but the nature of these interactions between the drug and proteins remain unclear. Finally, larger prospective clinical validations in multiple tumor types are required to investigate the correlations between SPARC expression and response to treatment. As of now, the only published clinical justification that establishes association between nab-PTX and SPARC expression is a retrospective analysis of a 60-patient clinical phase II study [59].

The impact of nanomaterial-protein interactions on personalized nanomedicine

From the preceding examples, it is clear that further understanding of the interactions between proteins and nanomaterials are required to further establish their potential for personalized medicine. The role of blood proteins on the clearance and immunological mechanisms must be better defined in order to more effectively implement nanoconstructs for therapeutic purposes. Patients display inter-individual variability in the circulating levels of various proteins (e.g., lipoproteins, immunoglobulins, cytokines). These differences can explain the variations in each patient’s response to therapeutics or their higher susceptibility to side effects (i.e., CARPA is observed only in a “reacting” subset of patient population) [43]. Similarly, the homeostasis of blood component can also be intensely affected by health conditions or diseases [66]. For example, physiological stress can trigger overexpression of acute-phase proteins and some of these proteins (e.g., C-reactive protein) can enhance complement activation and macrophage uptake when fixed on the surface of pathogens and senescent cells [67, 68]. The impact of such conditions on the fate of therapeutic nanomaterial must be ascertained before nanomedicine can be used efficiently in a variety of diseases.

In addition, nanomaterial-protein interactions must also be further understood to optimally exploit their beneficial effects on the activity or distribution of nanoconstructs. The example of SPARC is particularly relevant because if the protein is confirmed as a predictive biomarker of response to treatment, the albumin-based formulation would become the first nanomedicine approved for individualized therapy. However, extensive additional preclinical and clinical evidence is required before patients screened based on SPARC expression can receive personalized treatments.

2.2 Ligand-mediated interactions

Nanomaterials can be designed to specifically recognize a target with a surface ligand. These interactions can be utilized to preferentially concentrate a therapeutic nanoconstruct at a diseased tissue in vivo [69] or to bind and detect a biomarker for ex vivo diagnostic purposes [1]. The dimensions of the nanomaterials and the opportunity for polyvalent decoration of their surface with ligands contribute to their potential as effective homing and recognition devices. Throughout evolution, pathogens have exploited the multivalent patterning of a ligand on their surface to considerably enhance their affinity and tropism for their target [35, 70]. Likewise, on artificial constructs, a simple increase in the stoichiometry of a ligand can sometimes drastically enhance the ability to bind a substrate [71].

The decoration of a nanoparticle’s surface with a ligand can also trigger receptor-mediated endocytosis by cells expressing the right target on their membrane, a process that has considerable implications for targeted delivery [72]. Ligand-mediated interactions provide many opportunities for personalized medicine including differential spatial localization, intentional homing of nanoparticles to active diseased sites, and elimination of off-target adverse effects. Figure 3A and B illustrate the active binding of nanoparticles to cell surfaces for vascular targeting and tumor cell targeting. Ligand-functionalized nano-based therapeutic systems or imaging contrast agents therefore represent unrivaled platforms to improve the specificity and sensitivity of treatment and diagnostic tools.

Nanoparticles with ligands specific for endothelial cell surface markers nihms-401532-f0003

(A) Nanoparticles with ligands specific for endothelial cell surface markers allow for binding and accumulation to tumor vasculature. (B) Once in the tumor tissue, nanoparticles with ligands specific for tumor cell markers can actively bind to tumor cells,

The ligands used to decorate nanoparticles can include antibodies, engineered antibody fragments, proteins, peptides, small molecules, and aptamers [73]. For both applications, two types of targets exist: targets that are ubiquitously-expressed in all tissues and targets that are specific to diseased cells. Herein several examples of ligand-receptor interactions exploiting both categories will be presented, and special attention will be given to a few nanoplatforms that are targeted through ligand-receptor interactions and have made their way successfully to clinical trials [74].

2.2.1 Ubiquitous targets

The active targeting of drug delivery systems with transferrin (Tf), a 80-kDa blood-circulating glycoprotein, is a concept which dates back to the late-1980s [75]. Several characteristics make the targeting of transferrin receptors (TfR) attractive and an abundance of systems exploiting this internalization pathway have been designed. First, although the TfR is expressed in all types of tissue to satisfy the ferric (II) iron requirements of dividing cells, the hyper-proliferation of cancer cells makes it an attractive overexpressed target in tumors [76]. Secondly, the endocytosed TfR is very rapidly recycled to the cell surface after internalization [77, 78] which makes it an appealing, almost non-saturable, entryway into the cells. Thirdly, the TfR is believed to facilitate the transport of macromolecules and nanoconstructs across the blood-brain barrier [77], representing a rare opportunity to enable penetration to the central nervous system. For all these reasons, the targeting of therapeutic nanomaterials through Tf has been widely studied.

Recently, Davis et al. reported the first human trial of targeted siRNA delivery using polymeric nanoparticles containing Tf-modified cyclodextrin (CALAA-01) [79, 80]. In this study, human Tf was used as a targeting ligand for binding to TfR, which is typically upregulated on cancer cells and trigger cellular uptake via clathrin-coated pits. These targeted nanoparticles were administered intravenously to patients with melanoma where they circulated and localized in tumors (Figure 4). The Tf on the nanoparticle surface was able to bind to overexpressed TfR on cancer cells, and the nanoparticles were internalized via receptor-mediated endocytosis (Figure 4d). Tumor biopsies from melanoma patients obtained after treatment showed the presence of intracellularly localized nanoparticles in amounts that correlated with dose levels of the nanoparticles administered. Furthermore, a reduction was found in both the specific messenger RNA and the protein levels when compared to tissue obtained before dosing of the targeted nanoconstructs.

Figure 4

Assembly and function of targeted cyclodextrin nanoparticles containing siRNA. (a) Nanoparticles consist of four components: (i) a water-soluble, linear cyclodextrin-containing polymer (CDP), (ii) an adamantane (AD)-PEG conjugate (AD-PEG), (iii) the targeting

The receptor tyrosine kinase EGFR is another potent and well-studied target for anticancer drug delivery systems which is constitutively expressed on the surface of cells throughout the body. In response to the binding of its ligands (i.e., various growth factors), EGFR is significantly involved in cell signaling pathways associated with growth, differentiation and proliferation. EGFR exists on the cell surface and is overexpressed in multi-drug resistant (MDR) cancer cells [81, 82]. Milane et al. utilized this overexpression through the development of EGFR-targeted polymeric nanocarriers for the treatment of MDR cancer using paclitaxel (a common chemotherapeutic agent) and lonidamine (an experimental drug; mitochondrial hexokinase 2 inhibitor) [82]. The safety and efficacy of nanoparticle treatment were tested in a mouse orthotopic model of MDR human breast cancer. It was observed that this nanocarrier system demonstrated superior efficacy and safety relative to free drug combinations (paclitaxel/lonidamine solution) and single agent treatments in nanoparticle and solution forms. The targeted nanoparticles loaded with a combination of paclitaxel and lonidamine were the only treatment group that achieved sustained decrease in tumor volume. In addition, treatment with the EGFR-targeted lonidamine/paclitaxel nanoparticles decreased tumor density and altered the MDR phenotype of the tumor xenografts, decreasing the MDR character of the xenografts as evidenced by a drop in the expression of P-glycoprotein (Pgp) and EGFR. In another study, a versatile nanodiamond (ND) construct that incorporates anti-EGFR monoclonal antibodies (mAb), a fluorescent imaging agent and paclitaxel has been developed for multimodal imaging and the treatment of triple-negative subtype of breast cancer (TNBC) [83]. EGFR is expressed at high levels in at least 20% of breast cancers overall, but in 60-70% of patients with TNBC [84], which makes EGFR a potential treatment target. The enhanced cellular internalization of anti-EGFR mAb conjugated ND was only observed in the EGFR-overexpressing MDA-MB-231 cells but not in the basal EGFR expressing MCF7 cells. The data suggested that targeting through the mAb moiety increased specificity and internalization within EGFR-overexpressing breast cancer cells, which subsequently enhanced therapeutic activity of targeted conjugates. To monitor receptor-mediated endocytosis, Lidke et al. used quantum dots (QDs) conjugated to epidermal growth factor (EGF) to study erbB/HER receptor-mediated cellular response to EGF in living human epidermoid carcinoma A431 cells, assigning the mechanism of EGF-induced signaling to heterodimerization of erbB1 and erbB2 monomers and uncovering retrograde transport of endocytosed QD probes [85].

Finally, other examples of ubiquitously-occurring receptors being exploited for active targeting of ligand-functionalized therapeutics exist. For instance, various macromolecular drug conjugates and nanoparticulate systems were studied to take advantage of the overexpression of the folate receptor in tumor cells for the purpose of enhanced delivery as well as diagnosing and imaging malignant masses with improved specificity and sensitivity [86, 87]. Similarly, the retinol-binding protein, which is constitutively expressed in the brain, the spleen, the eyes, the genital organs and in lower quantities in the heart and lungs, was recently exploited to target stellate cells in the liver to alleviate cirrhotic fibrosis [88, 89]. In this approach, the favored non-specific distribution of the liposomes in the liver might contribute to enhancing the interactions between the nanomaterials and their target on the surface of the cells.

Cell-specific targets

Targeting to molecules that are differentially expressed at high levels by certain tissues offers a way to enhance accumulation at specific sites in the body. The exploitation of targets which are distinctively expressed in certain organs offers the possibility to further enhance the specificity of a treatment. The use of prostate-specific membrane antigen (PSMA) is a good example of a tissue-specific receptor that has been efficiently used to target anticancer drug-loaded nanoparticles. The first generation of prostate-specific nanoparticles incorporated PSMA-binding aptamers on their surface to promote internalization by cancer cells. In a mouse xenograft model, one single intratumoral injection of aptamer-functionalized nanoparticles loaded with docetaxel was able to show a considerably higher proportion of complete tumor regression and significantly prolonged survival rates [90]. Similar aptamer-decorated particles were also shown to be able to incorporate prodrugs of a hydrophilic platinum compound [91]. In order to translate these findings to the clinic, a formulation using a low molecular weight ligand with high affinity for PSMA was developed. These formulations using urea-based ligands provided the advantages of being easier to scale-up, while simultaneously not presenting the potential immunological problems associated with the presence of nucleic acids on the surface of the nanomaterial. A docetaxel-containing formulation functionalized with the PSMA-specific ligand, BIND-014, is currently in phase I clinical trials. Preliminary data showed stable disease in patients at doses below the commonly used regimen for the commercially-available, solvent-based docetaxel formulation [6].

Other specific targets have been investigated to optimize the interactions of therapeutic and diagnostic nanomaterials with diseased cells. For example, anti-CD33 monoclonal antibody has been successfully exploited to target leukemic cells since CD33 is a surface antigen expressed on over 80% of leukemia blast cells from acute myeloid leukemia (AML)-suffering patients but not on healthy cells [92]. Gemtuzumab, a monoclonal antibody to CD33 linked to a cytotoxic drug, was approved by the FDA in 2000 for use in patients over the age of 60 with relapsed AML. Upon the conjugation of anti-CD33 monoclonal antibody, the modified polymer/liposome hybrid nanovectors demonstrated enhanced internalization by CD33+ leukemic cell lines while limited interaction was found for nanovectors decorated with an isotype-matched control antibody [93]. In addition, the drug-loaded anti-CD33 nanoformulation exhibited the highest cytotoxicity against CD33+ leukemic cells, suggesting a promising targeted nanotherapeutics for the treatment of AML. The cancer cell-specific anti-nucleosome monoclonal antibody 2C5 (mAb 2C5), which recognizes the surface of various tumor cells (but not normal cells) via tumor cell surface-bound nucleosomes, was also attached to polymeric micelles, making the resulting micelles capable of specifically targeting a broad range of tumors [94]. Intravenous administration of tumor-specific 2C5 micelles loaded with paclitaxel into experimental mice bearing Lewis lung carcinoma resulted in an increased accumulation of paclitaxel in the tumor compared with free drug or paclitaxel in nontargeted micelles and in enhanced tumor growth inhibition.

The increasing availability of monoclonal antibodies for targeted therapy at large has fostered the interest of antibody-functionalized targeted nanomaterial for many years [9598]. However, the presence of these large biological macromolecules (Ab or Ab fragments) can seriously compromise their circulation times in the bloodstream, and their ability to traffic to their intended destination in vivo [99]. Therefore, large efforts have been put in the development of less immunogenic targeting moieties (e.g., peptides, small molecules) [100,101] which might possibly have brighter futures for in vivo applications.

2.2.3 Ligand-mediated in vitro diagnosis

In comparison, the immunologic properties of antibodies are much less of a hindrance for ex vivo diagnostic applications, and the field has benefited greatly from the specific-binding properties of these molecules to recognize and detect biomarkers of interest [1]. Several nanomaterials can be modified with different combinations of specific markers to rapidly screen molecular profiling of small populations of cancer cells at good signal-to-noise levels [102], which is of clinical importance for early cancer detection. An example of such technique named “bioorthogonal nanoparticle detection” (BOND) was developed by Weissleder and colleagues [102]. In this work, live cells were labeled with trans-cyclooctene-modified antibodies (anti-HER-2, EpCAM and EGFR, respectively) followed by coupling with tetrazine-modified fluorescent-labeled iron oxide nanoparticles (Figure 5A and B). The transverse relaxation rate (R2) was measured for ~ 1000 cells, a sample size in line with clinical specimens, using a miniaturized diagnostic magnetic resonance detector. As shown in Figure 5C, markers signals were nearly at normal levels for benign fibroblasts and leukocytes (except for CD45, naturally expressed in the latter) while tumor cells showed considerable heterogeneity in the expression of the different markers. The nuclear magnetic resonance (NMR) signals correlated well with the actual expression levels that were independently determined by flow cytometry using a larger sample size (Figure 5C). This BOND platform demonstrated its application in clinically-oriented molecular profiling by utilizing the polyvalent interactions between engineered nanomaterials and their targets of interest on cell surfaces.

Figure 5

(A and B) Two-step process for targeting biomarkers on cancer cells. Live cells are labeled with TCO-modified antibodies followed by covalent reaction with Tz-modified fluorescent0labeled iron oxide nanoparticles. (C) Cell profiling using a miniaturized

Similarly, small molecules can also be utilized for specific recognition. For example, the self-assembly properties of mannose-functionalized nanoobjects upon interactions with the lectin-coated E. Coli bacterial wall was utilized to detect the presence of the pathogen at different concentrations [103]. In this work, the material becomes highly fluorescent by spatially-rearranging itself in a polymeric fiber structure upon interaction with bacteria. Similarly, in a two-step approach, Weissleder et al. decorated the surface of gram-positive bacteria by targeting the surface D-Ala-D-Ala functional groups on the pathogen with vancomycin-trans-cyclooctene conjugates [104]. The presence of these conjugates is subsequently detected using tetrazine-functionalized magnetofluorescent nanoparticles which can attach covalently in situ with the cyclooctene moieties [102, 104].

Selection of ligands

Depending on the intended application, the ligands chosen in the nanomaterial design will highly influence the efficacy of the system. For ex vivo diagnosis, the nanoparticles are expected to immobilize on the cell surface via ligand-receptor interactions as a diagnostic tag. The high affinity and specificity of the ligands are of paramount importance for the reduction of false negatives and positives, respectively. In contrast, nanoparticles that serve as delivery vehicles for drugs will have other considerations. For example, considering that intracellular delivery of drug-loaded nanoparticles could provide enhanced therapeutic effects, selection techniques have been developed to distinguish internalizing ligands from non-internalizing ligands [105, 106]. Hild et al. elegantly showed that QDs modified with agonists binding to G protein-coupled receptors could be internalized whereas the same nanoparticles modified with antagonists could not [107]. The functionalization of the nanomaterial with the appropriate ligand dictates the fate of the nanoparticle, allowing for either simple flagging of the cell surface or further uptake to deliver a payload using the same target. Recently, Xiao et al. designed a cell-uptake selection strategy to isolate a group of cancer-cell specific internalizing RNA aptamers (Figure 6A) [108]. In this strategy, selection was carried out against prostate cancer cells using counter selection with non-prostate and normal prostate cells to remove non-specific strands. The internalizing ligands were preferentially collected by deleting non-internalizing, membrane-bound aptamers. The cell uptake properties of nanoparticles functionalized with the identified aptamers were confirmed to be highly specific and efficient (Figure 6B).

selection process for isolating RNA aptamers capable of cell-specific internalization in prostate cancer cells nihms-401532-f0006

selection process for isolating RNA aptamers capable of cell-specific internalization in prostate cancer cells nihms-401532-f0006

(A) Cell-uptake selection process for isolating RNA aptamers capable of cell-specific internalization in prostate cancer cells. (B) Visualization of aptamer-functionalized nanoparticle internalization by PC3 cells using confocal fluorescence microscopy.

Further efforts are now underway to identify ligands with the appropriate affinity and to apply these binding ligands to specifically engineer nanomaterials for diagnosis and targeted therapy [109]. One might note, however, that for a specific ligand, the internalizing properties of the nanomaterial can also depend on multiple physicochemical properties, like size [110] and surface density [111]. The biological processes emerging from successful internalization of the nanomaterials by the cells will be discussed in Section 2.3.

Considerations for personalized medicine

In the near future, the availability of ligand-functionalized therapeutic nanomaterial will have a clear impact on the individualized treatment of diseases. In this context, the detection and monitoring of the target expression before initiating therapy and during the whole treatment will clearly be of utmost importance. Similarly, multivalent nanoparticles are complex objects in which behavior depends on a variety of physicochemical properties [6, 112]. Presently, efforts should be made to better understand how ligand-functionalized nanomaterials interact with their targets. In parallel, a better comprehension of the correlations between target expression patterns and cancer prognosis is also required. When both of these aspects are addressed, the therapeutic targets to select for the rational design of nanomedicine will become clearer.

Interactions during intracellular processing

Once endocytosed, nanomaterials are internalized and remain entrapped in transport vesicles which traffic along the endolysosomal scaffold, thereby exerting key effects on subcellular organelles. Intracellular trafficking and the fate of nanomaterials are linked to their physicochemical properties and endocytic pathways [113116]. For example, nanoparticles taken up by clathrin-dependent receptor-mediated endocytosis (RME) are typically destined for lysosomal degradation; whereas, clathrin-independent RME internalization leads to endosomal accumulation and sorting to a nondegradative path [116]. While some drug delivery systems aim to avoid lysosomal degradation [117], recent studies have utilized directed delivery to this environment for the enzymatic release of therapeutics [116, 118]. Understanding the key intracellular interactions of nanoparticles has allowed researchers to engineer nanoparticles for highly specialized delivery. Appropriate design and engineering of nanocarriers could therefore allow for controlled intracellular delivery of therapeutics to individual intracellular compartments, which provides benefits to therapies associated with these unique organelles, including cancer therapy, gene therapy, and lysosomal storage disease (LSD) treatments. Furthermore, by offering an alternative to passive diffusion as an entryway into the cells, the design of nanomaterials that can be internalized by receptor-mediated endocytosis and thus release their active drugs inside subcellular organelles might provide a useful means to circumvent efflux pump-mediated drug resistance [119]. Here we briefly discuss several examples where the physiological endosomal and lysosomal environment can be exploited to develop responsive drug delivery systems.

Intracellular drug release

Polymer-drug conjugates were among the earliest formulations designed to preferentially release their payload inside the cell. Poly[N-(2-hydroxypropyl)methacrylamide] (HPMA) was the first synthetic polymer-drug conjugate to enter clinical trials in 1994. Others, like degradable polyglutamate (PGA), have also been widely clinically investigated as anticancer nanomedicines [118]. These nanosized drug delivery systems are based on the covalent conjugation of chemotherapeutics to hydrophilic polymers, which markedly improves solubility as well as alters drug biodistribution and pharmacokinetics. Conjugates have longer half-life (typically > 1 h) than free drug (< 5 min) when circulating in the blood, leading to significantly increased drug concentrations in tumors [120122]. Since most drugs need to be released from the macromolecule to exert their pharmacological effect, the nature of the linker between the drug and the polymer is therefore of crucial importance (Figure 7). Although the chemical reacting groups on both the macromolecule and the drug dictate the character of the linker available, various classes of bonds with passive or physiologically-triggered cleavage have been studied [123]. Clinical experience has shown that rapid degradation of ester bonds in the bloodstream could lead to suboptimal distribution of the drug in the tumor [124127]. Therefore, if the drug exerts its effects through an intracellular pharmacological receptor, it can be beneficial to design the conjugate with a lysosomally-degradable peptidyl linker (e.g., Gly-Phe-Leu-Gly). This type of linker is stable in the bloodstream but can be cleaved by the lysosomal protease cathepsin B once internalized over 24-48 h [114, 118, 128]. Lysosomes and lysosomal hydrolase malfunctions have been associated with several aspects of malignant transformation, including the loss of cell growth control, altered regulation of cell death, and acquisition of chemo-resistance and of metastatic potential [129]. Lysosomal protease-mediated drug release is thus a key conceptual design principle for the chemotherapy of cancer with nanomedicine [118]. An exciting clinical program is assessing a PGA-paclitaxel conjugate (CT-2103; Opaxio) using the Gly-Phe-Leu-Gly linker [120, 130]. In this system, paclitaxel is released to a small extent by slow hydrolytic release, but is released mainly through lysosomal cathepsin B degradation of the polymer backbone [131]. Experiments in cathepsin-B-homozygous knockout mice confirmed the importance of enzyme degradation and intracellular delivery. Clinical studies showed that a significant number of patients responded to stable disease profiles, particularly in patients with mesothelioma, renal cell carcinoma, NSCLC and in paclitaxel-resistant ovarian cancer [120]. In a recent randomized phase III clinical trial, PGA-paclitaxel demonstrated reduced severe side effects and superior therapeutic profiles compared with gemcitabine or vinorelbine as a first-line treatment for poor performance status NSCLC patients [132, 133]. Additionally, in comparison with men this trial showed increased survival in women treated with PGA-paclitaxel, specially marked in pre-menopausal women [134]. It should also be noted that activity might correlate with estrogen levels which increase expression of cathepsin B [135]. If these findings are confirmed in larger studies, PGA-paclitaxel could be used as a potential gender-specific first-line therapy to treat women with NSCLC.

Tumor cell internalization of polymer-drug conjugates nihms-401532-f0007

Tumor cell internalization of polymer-drug conjugates nihms-401532-f0007

Tumor cell internalization of polymer-drug conjugates occurs through several possible mechanisms, including fluid-phase pinocytosis (in solution), non-specific membrane binding (due to hydrophobic or charge interactions) resulting in receptor-mediated

In addition to lysosomally-cleavable peptide linkers, pH-sensitive cis-aconityl, hydrazone and acetal linkages that respond to changes in intracellular pH have also been used [115]. They can be hydrolyzed under the local acidic pH (6.5-4) within endosomal and lysosomal vesicles [136]. As such, pH-sensitive [137140] or reduction-specific [141, 142] nanoparticle formulations have been designed to facilitate the intracellular delivery of active components. Once low molecular weight drugs are released in the endosome, they are free to escape the intracellular vesicles by diffusion. However, for high molecular weight or charged compounds (e.g., proteins or nucleic acids), passive diffusion through the membrane is difficult and the formulation needs to further provide endosome-disruptive properties to allow for intracytosolic delivery.

Considerable effort has been made to design various types of endosomolytic formulations, especially for the delivery of siRNA and other therapeutic nucleic acids. siRNA must escape from endosome compartments before endosomal/lysosomal degradation occurs in order to exert their gene silencing activity. A wide range of delivery systems have been developed, including dendrimers, liposomes, cationic lipid-like compounds (lipidoids), cyclodextrin, polyethyleneimine (PEI) and others, to facilitate endosomal escape and ensure cytosolic delivery of the therapeutics. In these systems, membrane-disruptive properties can be obtained by using proteins and peptides [143, 144], polymers [145, 146] or simply by incorporating a high number of ionisable amine groups to exploit the proton sponge effect [117]. Figure 8 illustrates the mechanisms of the proton sponge effect, in which nucleic acids are released from polyamine-containing nanoparticles in acidic endosomes. The key to understanding the proton pump hypothesis is the lysosomal proton pump (v-ATPase), which is responsible for acidification of the lysosomal compartment. Within acidifying lysosomal compartments, unsaturated amines on the nanoparticle surface are capable of sequestering protons that are supplied by the proton pump, continuing pump activity and leading to the retention of one Cl- anion and one water molecule for each proton that enters the lysosome. Ultimately, this process causes lysosomal swelling and rupture, leading to siRNA-loaded particle deposition in the cytoplasm [20].

The proton sponge effect nihms-401532-f0008

The proton sponge effect nihms-401532-f0008

The proton sponge effect allows for cationic nanoparticles to escape endosomal and lysosomal vesicles and enter the cytoplasm. When cationic nanoparticles enter acidic vesicles, unsaturated amino groups sequester protons supplied by v-ATPase (proton pump).

Finally, increasing attention has been focused on the targeting of therapeutic agents to specific organelles. This can be achieved by attaching subcellular targeting ligands on the surface of nanomaterials to redirect their accumulation to desired compartments. For instance, Niemann-Pick type A and B are rare genetic LSDs associated with a deficiency of acid sphingomyelinase (ASM), a single enzyme required for the metabolism of lipids, glycoproteins or mucopolysaccharides [147]. A recent study demonstrated that the specific delivery of recombinant ASM to lysosomes by nanocarriers coated with antibody against intercellular adhesion molecule-1 (ICAM-1) could alleviate lysosomal lipid accumulation and improve the efficacy of enzyme replacement therapy [147].

Considerations for personalized medicine

The utilization of intracellular enzymes to trigger the therapeutic activity of nanoconstructs has considerable implications for personalized medicine. As differences in enzyme expression between individuals and pathologies are expected, the sophisticated systems described above might prove more beneficial in a certain subset of patient populations. For example, if the effect of gender-specific cathepsin B expression on the efficacy of PGA-paclitaxel is further confirmed in clinical trials, the appeal of the drug conjugate to treat women-specific cancer types (e.g., ovarian, breast) will certainly be strengthened. More generally, the linkers that can be cleaved by an intracellular protease of interest (e.g., Gly-Phe-Leu-Gly linker) might turn out to be very useful for the design of future drug delivery systems to treat patients overexpressing the target proteases.

The development of drug delivery systems which can effectively deliver their payload inside the cells is also crucial for the future of nucleic acid-based therapies. These therapies hold great promises as treatment and prevention methods for various diseases. For example, successful delivery of siRNA could inhibit the expression of MDR transporters and may restore tumors’ chemosensitivity to treatment [148, 149]. In this context, the combination of conventional chemotherapeutics with siRNA-based therapeutics represents a promising therapy for patients with chemoresistance malignancies.

Engineered nanomaterials for personalized medicine applications

Nanomaterials have evolved significantly over the last few years and nanomedicine has brought unprecedented advances in the diagnosis, imaging and treatment of a variety of diseases. Presently, nearly 250 nano-sized products exist in various stages of development, including nanomaterials with different compositions, physicochemical characteristics, surface functionality and geometry [150]. The following section will explore some examples of the applications of nanomaterials relevant to personalized medicine and the associated design features based on an understanding of nano-bio interactions.

Ex vivo diagnostics

The identification of biomarkers represents the first step in attaining an individually tailored medicine. Biomarkers could be mutant genes, RNAs, proteins, lipids or metabolites that are associated with a specific pathological stage or clinical outcome. Molecular profiling studies on biomarker discoveries have shown that gene expression patterns can be used to identify cancer classification, yielding new insights into tumor pathology such as stage, grade, clinical course and response to treatment [151]. Alizadeh et al. were the first to report the correlation between gene expression patterns and clinically distinct subtypes of cancer based on their study of diffuse large B-cell lymphoma [152]. The concept of a specific molecular profile for each patient’s tumor was later validated [153, 154]. By linking biomarkers with cancer behavior, it is possible to improve diagnosis, assess response to treatment and evaluate progression of cancer based on each patient’s molecular profile [155].

The enhanced interactions that occur between nanomaterials and biomacromolecules (e.g., proteins and nucleic acids) markedly improve the sensitivities of current detection methods. Nanomaterial surfaces can be tailored to selectively bind biomarkers and sequester them for subsequent high-sensitivity proteomic tests [156]. For example, nanoparticles containing DNA sequences complementary to messenger RNAs of biomarker genes can be used as simple and semi-quantitative beacons for the detection of the expression patterns of biomarkers in a single cell [157]. A bio-barcode assay has been recently developed based on oligonucleotide modified gold nanoparticles for high-throughput detection of nucleic acid and protein targets [15]. This approach utilizes gold nanoparticles functionalized with oligonucleotides and antibodies to target either a patient’s DNA or a protein sample and can detect multiple markers with high accuracy (95%). This nanoparticle-based bio-barcode assay has extraordinarily high sensitivity (10−18 M) similar to that of PCR-based assays but without the need for lengthy amplification procedures [14, 15]. Furthermore, this approach does not suffer from the problems often associated with conventional fluorescent probes for microarray labeling, such as photobleaching (loss of signal after exposure to light), which opens a new avenue for developing highly selective panel assays for early detection of a wide range of diseases. This technology has been approved by the FDA for genetic screening to determine drug sensitivity and to detect genetic mutations. It is currently being validated for the detection of proteins found in prostate cancer, ovarian cancer, and Alzheimer’s disease [16].

Likewise, the simultaneous use of nanomaterials with different ligands can allow concurrent detection and precise profiling of the epitopes present in cell specimens. Yezhelyev et al. demonstrated the detection and quantification of multiple biomarkers in human breast cancer cells and biopsies using QDs conjugated with primary antibodies against HER2, ER, PR, EGFR and mTOR [158]. The parallel evaluations of three specimens revealed distinct molecular profiles: one tumor biopsy over-expressed EGFR, another ER and PR, and the third one ER and HER2. This high throughput ex vivo screening analysis could be used to identify the molecular signatures of an individual patient’s tumor, and to correlate a panel of cancer biomarkers with the clinically distinct subset of biomarkers present in the patient’s tumor.

Nanomaterials can also be used to harvest disease-relevant biomarkers in the sample for early detection. Luchini et al. used Poly(N-isopropylacrylamide) hydrogel nanoparticles to harvest and concentrate low molecular weight (LMW) biomarkers (e.g., proteins and metabolites) from biological fluids via electrostatic interactions [159]. The hydrogel nanoparticles possessed defined porosity and negatively- and positively-charged groups for a rapid one-step sequestration and concentration of the ionized LMW fractions from complex serum molecules. The captured peptides or proteins were protected from further enzymatic degradation and were readily extracted from the particles by electrophoresis. When using the nanoporous sieves presented in this study, the proteins are denatured when eluted out of particles and then analyzed by MS for biomarker discovery. The denaturation step may hinder subsequent applications that require the analytes to be in their native state (e.g., immunoassays, enzymatic assays). Therefore, it is necessary to develop novel nanoparticles which preserve the conformational integrity of the isolated proteins. Combined with current proteomic technologies, these nanoparticles provide enormous enhancement of rare biomarkers associated with disease.

In vivo imaging

In recent years, several medical diagnostic technologies have been developed for clinical imaging and detection, including fluorescence imaging, positron emission tomography (PET), single-photon-emission computer tomography (SPET), and magnetic resonance imaging (MRI). These methods require injection of fluorescent trackers, radionuclides or contrast agents. The development of contrast agents able to target specific molecules could advance the molecular characterization of disease, from the identification of disease-associated molecular pathways to the clinical monitoring of relevant biomarkers before and after treatment [5]. Nanomaterials have been explored as platforms for the development of novel contrast agents because they are easily functionalized, possess high contrast, and have tunable physicochemical properties [5].

Various formulations of superparamagnetic iron oxide nanoparticles (SPIONs) are approved or are under clinical investigation for imaging. A key advantage of SPIONs in comparison to other inorganic or heavy metal-based MRI contrast agents is their innocuity. Particles can be degraded to iron and iron oxides molecules that are metabolized, stored in intracellular pools as ferritin, and incorporated into hemoglobin [160]. Administration of 100-200 mg iron/kg in rodent models elicited no detectable side effects [160, 161], a dose well above that used for MRI procedures (< 5 mg/kg). Ferumoxides (Feridex I.V.®) and ferucarbotan (Resovist®) are clinically approved as the first generation SPIONs and are suitable for T2- and T2*-weighted imaging. These contrast agents rely on passive targeting strategies to detect and evaluate lesions of the liver associated with an alteration in the MPS [162]. Their distinctive in vivo behavior dictates their utility in the clinic: ferumoxides, administered via slow infusion, for the detection of small focal lesions with high accuracy during delayed phase imaging [163] and ferocarbotan, which can be administered as a rapid bolus, to produce higher liver-to-tumor contrast during dynamic imaging [164]. Two other SPIONs formulations are currently in clinical trials as contrast agents for MR angiography (MRA). Supravist (Ferucarbotran, a T1-weighted reformulation of Resovist) and VSOP-C184 (7-nm, citrate-coated SPION formulation) have generated first-class images comparable to those using gadolinium (Gd) based agents but with favorable safety, tolerability, and efficacy data [165167]. These nanoparticle-based MRA agents will likely play an important role in advancing angiography as imaging modality for personalized medicine due to their advantages of long plasma half-life and ultra-small sizes that facilitate the detection of small vessels with slow and/or complex flow [165, 168]. SPIONs are now being developed to track cell movement in vivo following transplantation with the long-term goal of developing and monitoring personalized cell-based therapies [169].

For similar applications and as an alternative approach to the use of MRI, others have utilized QDs as probes for high resolution molecular imaging of cellular components and for tracking a cell’s activities and movements inside the body [170, 171]. With the capability of single-cell detection, these nanomaterials enable the real-time characterization of properties of certain cancer cells that distinguish them from closely related non-pathogenic cells.

Since targeted cancer treatments are selected on the basis of the expression patterns of specific biomarkers, there is an urgent need for detecting and monitoring the changes in biomarker expression in situ in a non-invasive manner. Nanoparticles are in development to maximize the specificity of contrast agents by exploiting receptor-ligand interactions. Targeted nanoparticles are able to accumulate at sites where the molecular target is expressed, increasing the local concentration of contrast agents.

One example is the 18F-labeled ABY-025 affibody, a compact three-helix bundle that binds HER-2 [5, 172]. When tested in animals, the 18F-labeled ABY-025 was able to directly assess HER-2 expression in vivousing PET and monitor changes in receptor expression in response to therapeutic interventions [172]. Lee and colleagues also reported that herceptin-conjugated magnetic nanoparticles that target HER-2 could significantly enhance MR sensitivity compared with currently available probes, enabling the detection of a tumor mass as small as 50 mg [173]. The correlation of the signal observed by non-invasive imaging modalities with receptor expression could be utilized to perform follow-up studies without the need for biopsies to evaluate treatment efficacy and direct therapy tailoring.

In the near future, in vivo imaging techniques using nanomaterials will go beyond the field of oncology. Monocrystalline iron oxide particles functionalized with anti-myosin Fab fragments are in preclinical development to detect myocardial infarcts [174]. Similarly, combination approaches using two or more imaging modalities are particularly appealing. Cross-linked iron oxide nanoparticles (CLION) activated by proteases were prepared by encapsulating iron oxide nanoparticles within polymer-Cy5.5 conjugates, combining fluorescence and MRI imaging to assess the enzymatic activity in plaques [175178]. In this system, the fluorescence of the multiple Cy5.5 molecules was quenched until the lysine-lysine bonds were cleaved by cathepsin B, which is upregulated in atherosclerotic lesions. The CLION developed initially for tomography was also able to image vulnerable plaques and infarcted lesions. Other multi-modal nanoparticle-based contrast agents include fluorescently labeled gadolinium-conjugated gold nanoparticles [179] and paramagnetic lipid-coated QDs [180].

Theranostic nanoparticles

Theranostic nanoparticles integrate molecular imaging and drug delivery, allowing the imaging of therapeutic delivery as well as follow-up studies to assess treatment efficacy [181183]. Theranostic nanoparticles can serve as useful tools to explore the fundamental process of drug release after cellular internalization of nanoparticles, which could provide key insights into the rational design of targeted nanocarriers for personalized treatment.

For example, a smart core-shell QD platform, namely QD-aptamer (doxorubicin), was engineered to sense drug release (Figure 9) [183]. A10 RNA aptamer was used to recognize the extracellular domain of PSMA. The intercalation of doxorubicin within the double-stranded “GC” dinucleotide segment of the A10 aptamer on the surface of QDs resulted in quenching of both QD and doxorubicin fluorescence (“OFF” state). Upon receptor-mediated endocytosis of targeted QD conjugates into PSMA-expressing prostate cancer cells, the released doxorubicin induced the recovery of fluorescence from both the QDs and doxorubicin (“ON” state). This system allowed sensing of the intracellular release of doxorubicin and enabled the synchronous fluorescent localization and killing of cancer cells.

QD-aptamer (doxorubicin) system

QD-aptamer (doxorubicin) system

(a) Schematic of a QD-aptamer (doxorubicin) system capable of fluorescence resonance energy transfer (FRET). Doxorubicin is able to intercalate with the A10 PSMA aptamer bound to the QD surface, quenching both QD and doxorubicin fluorescence through a

Another elegant design is the drug-containing paramagnetic nanoparticles targeted to various atherosclerotic plaque lesions components including the αvβ3 integrin [184], fibrin [185], and collagen type III [186], allowing both targeted MR imaging and drug delivery. Animal studies were performed using αvβ3-targeted nanoparticles containing the anti-angiogenesis drug fumagillin repeatedly administered to atherosclerotic rabbits [184]. The results demonstrated that nanoparticle accumulation enabled imaging of the atherosclerotic lesion and generated an anti-angiogenic effect. Advances in this field will pave the way for detecting disease, targeting therapies, and assessing response with one single nanoparticle agent.

Targeted therapies

One of the major avenues of personalized nanomedicine is the development of delivery platforms that can specifically target diseased tissues (i.e., tumor) [187]. In theory, drug targeting would not only ensure a more effective treatment of the target tissue, but also permit a much lower overall dose to be administered than conventional drug delivery, reducing adverse side effects and increasing patient compliance. Two approaches, both passive and active targeting, have been utilized to home nanoparticles to active sites in disease conditions.

Passive targeting takes advantage of the inherent biophysicochemical properties of the nanoparticles (size, shape, charge and flexibility etc.). This phenomenon is most often associated with EPR effects in tumors. A recent in vivo breast cancer study in rodents showed that the passive targeting approach can be used to personalize treatment [188]. Individualized therapy in its simplest form could be achieved by studying the intratumoral accumulation of iodine-containing liposomes by X-ray tomography to predict the deposition of therapeutic doxorubicin-loaded liposomes in the diseased tissue [188]. If tumor accumulation is found to correlate with the patient’s susceptibility to treatment, this approach could be used to identify individuals with lesions possessing leaky vasculature and who would benefit the most from nanosized formulation.

Actively targeted personalized therapies involve surface modification of drug carriers with ligands such as antibodies, peptides, aptamers, and small molecules that specifically bind to tissues of interest. The drug can then be delivered to the target cells through receptor-mediated internalizing interactions as presented in section 2.2 and 2.3. The binding targets of the modified nanocarriers include differentially overexpressed receptors/antigens on the plasma membrane of disease cells and the differentially overexpressed extra-cellular matrix proteins in diseased tissues. For instance, a peptide-conjugated nanoparticle was shown to target the vascular basement membrane exposed on injured vasculature [189]. The C-11 peptide decorating the nanoparticles showed high affinity for collagen IV, which represents 50% of the vascular basement membrane. This targeted nanoparticle platform holds particular promise for treatments of targeted blood vessel walls such as catheter or stent-induced cardiovascular injuries.

Intracellular organelles can also be targeted. Direct DNA delivery to the mitochondrial matrix has been suggested for the treatment of genetic diseases associated with mitochondrial genome defects [190]. Lee et al. conjugated the mitochondrial leader peptide, a peptide derived from the nucleocytosol-expressed but mitochondria-localized ornithine transcarbamylase, to polyethylenimine using a disulfide bond to render the resultant PEI-MLP conjugates mitochondriotropic [190]. In vitro delivery tests of rhodamine-labeled DNA into living cells demonstrated that PEI-MLP/DNA complexes were localized at mitochondrial sites. The data suggested that PEI-MLP can deliver DNA to the mitochondrial sites and may be useful for the development of direct mitochondrial gene therapy.

Combination therapies

The combination of multiple therapeutic agents in a single nanocarrier has been proposed as an alternative approach to increase the efficacy of anticancer treatments through synergistic interactions while mitigating drug resistance [191]. As a proof of concept, Kolishetti et al. developed a targeted therapeutic nanoparticle system for co-delivery of cisplatin and docetaxel, two drugs with different metabolic targets, to prostate cancer cells [192]. In this approach, a Pt(IV) cisplatin prodrug-polymer conjugate was blended with PLGA-PEG and docetaxel to form nanoparticles (Figure 10) [192]. The dual-drug encapsulated nanoparticles were then conjugated with the A10 aptamer to target PSMA overexpressing cancer cells. In vitro studies demonstrated that the aptamer targeted, dual-drug loaded nanoparticles were 5 to 10 times more cytotoxic than respective single drug encapsulating nanoparticles.

Pt(IV)-PLA drug conjugates were blended with PLGA-PEG and docetaxel to form nanoparticles  nihms-401532-f0010

Pt(IV)-PLA drug conjugates were blended with PLGA-PEG and docetaxel to form nanoparticles nihms-401532-f0010

Pt(IV)-PLA drug conjugates were blended with PLGA-PEG and docetaxel to form nanoparticles capable of delivering chemotherapy drug combinations. The nanoparticle surface was then functionalized with the A10 aptamer to target the nanoparticles to PSMA receptors.

The release of multiple payloads can also be tailored to enhance efficacy. Sengupta et al. synthesized a biphasic “nanocell” with a lipid layer containing combretastatin and a hydrophobic core containing PLGA-doxorubicin conjugates [193]. This construct enabled temporal release of the two drugs: combrestatin was released first to collapse the blood vessels and trap the particles inside the tumor, followed by the release of doxorubicin to kill the tumor cells focally without being diluted by the blood circulation. The polymeric nanocell was compared with liposomes co-encapsulating combretastatin and doxorubicin, which lack the differential drug release kinetics. In murine models bearing Lewis lung carcinoma and B16/F10 melanoma, the nanocell platform resulted in better tumor reduction, longer median survival time, and lower systemic toxicity. This study demonstrated that sequential delivery and scheduling of combinatorial drugs are important parameters that influence drug synergism and side effects.

Finally, combination strategies are particularly appealing in the case of siRNA delivery where the knockdown of specific genes can lead to tremendous improvement in the efficiency of drugs. For instance, MDR-1 gene silencing and paclitaxel co-therapy in PLGA nanoparticles was shown to significantly contribute in overcoming tumor multidrug resistance in vivo [194]. Taken together, the development of combination nanotherapeutic strategies that combine gene silencing and drug delivery could provide a more potent therapeutic effect, especially in refractory tumors.

Research on the development of combinational therapies is on the rise. However, this area will benefit from further investigations involving: (1) the discovery of efficacious molecular targets in cancer cells and better understanding of drug activity in these cells; (2) understanding the pharmacokinetics of different drugs by simultaneously delivering multiple therapeutic agents to the target site; (3) the demonstration of the contribution of each component of the combination to the treatment effect; (4) the development of nanocarriers that allow for precisely-controlled loading and release of two or more drugs with variable properties; and (5) the evaluation of responses to treatment among patients following the use of combination therapies.

Challenges with nanomaterials for personalized nanomedicine
Toxicity of nanomaterials

The uncertain health hazard potential of nanomaterials is probably the most significant hurdle for regulatory approval and commercialization of nanomedical products [195]. The unique physical and chemical properties of nanomaterials (i.e. small size, increased reactivity, high surface-to-volume ratio, etc.) while are likely to provide health benefits, may also be associated with deleterious effects on cells and tissues [187, 196]. Nanomaterials have dimensions similar to organelles found in the cell and have the potential to interfere with vital cellular functions, resulting in potential toxicity [197]. While engineered nanomaterials offer improved half-life circulation, this implies that the time required for clearance of loaded drug will also be prolonged. Accordingly, some nanoparticles may be retained in the body not only for days, but potentially for years. Some nanomaterials such as metal nanoparticles, metal oxide nanoparticles, QDs, fullerenes and fibrous nanomaterials were found to induce chromosomal fragmentation, DNA strand breakages, point mutations, oxidative DNA adducts and alterations in gene expression [198], sometimes even through cellular barriers [199]. In these cases, the safety profile becomes a major concern. Although there have been no reported examples of clinical toxicity due to nanomaterials thus far, early studies indicate that nanomaterials could initiate adverse biological interactions that can lead to toxicological outcomes [200]. Since the mechanisms and severity of nanotoxicity are not fully predictable or testable with current toxicological methods, the toxicity of nanomaterials is rapidly emerging as an important area of tangential study in the nanomedicine research field.

There are many different factors to consider when designing nanomaterials and an understanding of how different parameters affect toxicity can aid in designing safer nanomaterials for medical applications. Some important parameters to consider include size, shape, surface area, charge, state of aggregation, crystallinity, and the potential to generate reactive oxygen species (ROS) [200]. Size is a significant factor and can influence the distribution and toxicity of a material. Studies with gold nanoparticles (AuNPs) in four different cell lines demonstrated that both toxicity and the mechanism of cell death were size-dependent [201]. 1.4 nm AuNPs were 60-fold more toxic than 15 nm AuNPs and cell death from 1.4 nm AuNPs was due to necrosis while 1.2 nm AuNPs caused apoptosis of the cells [201]. The toxicity of the 1.4 nm AuNPs was due to the ability to intercalate with DNA while AuNPs of larger sizes were unable to intercalate with the DNA [202]. Size can affect both the distribution within the body as well as the distribution within a cell [203, 204]. Studies of QDs in macrophages have shown that QD size influences subcellular trafficking, with the smallest QDs able to target histones in the cell nucleus [204]. Composition is another factor that influences the toxicity of nanomaterials. QDs may create a health hazard due to toxic heavy metal elements such as cadmium that are incorporated into the QDs [205]. It may, however, be possible to reduce the potential toxicity of nanomaterials such as QDs by adding a coating or nanoshell [206].

Carbon nanotubes (CNTs) are a nanomaterial that has great potential in various medical applications. However, concerns have emerged over its toxicity due to its shape, which resembles asbestos fibers [207]. Longer CNTs have been shown to act like indigestible fibers that lead to frustrated phagocytosis and granuloma formation [208]. Studies in mice have shown that frustrated phagocytosis can lead to massive release of oxygen radicals by immune cells, which can result in chronic granulomatous inflammation and potentially mesothelioma if the CNTs are in the pleural cavity or peritoneum [209]. CNTs can cause mutagenic effects through the generation of inflammation and direct interaction with components of the cell. Exposure of mice to CNTs by inhalation increased the rate of mutation of the K-ras gene locus in the lung, with the mutations occurring during times of maximum inflammation in the tissue [210]. CNTs can also interact directly with the cellular cytoskeleton, including the microtubule system during the formation of the mitotic spindle apparatus, leading to aberrant cell division [211].

Nanomaterials such as titanium dioxide can cause toxicity based on crystalline structure. Cytotoxic studies showed that the anatase form of titanium dioxide was 100 times more toxic than the rutile form, and that the toxicity correlated with the generation of ROS under UV light [212]. Oxidative stress and the generation of ROS is a key injury mechanism that promotes inflammation and atherogenesis, resulting in adverse health events [213, 214]. The surface composition also plays a role in nanomaterial toxicity. Discontinuous crystal planes and material defects can act as sites for ROS generation [200]. The presence of transition metals or organic chemicals on the surface of nanomaterials can also result in oxygen radical formation and oxidative stress [215].

The degradability of a nanomaterial is another important parameter to consider for toxicity. If nondegradable nanomaterials have no mechanism of clearance from the body, they can accumulate in organs and cells and exert toxic effects. Injectable gold compounds have been used for the treatment of rheumatoid arthritis and the accumulation of gold compounds in the body over time may cause toxic effects in patients [216]. However, biodegradable materials may also cause toxic effects if the degraded components of the material are toxic [217].

In addition, the nanomaterial charge is a significant contributor to the toxicity of the material. Increased in vitro cytotoxicity and in vivo pulmonary toxicity has been observed for cationic polystyrene nanospheres when compared with anionic or neutral polystyrene [218, 219]. Interestingly, the mechanism of toxicity for cationic nanospheres was dependent on the cell type and uptake mechanism [219]. In macrophages, particles entered the cell through phagosomes and caused lysosomal rupture due to the proton sponge effect. Upon entry into the cytosol, the particles caused an increase in Ca2+ uptake by mitochondria and oxidative stress, leading to apoptosis. In epithelial cells, cationic particles entered through caveolae. The particles also induced an increase in mitochondrial Ca2+ uptake and oxidative stress, but cell death was by necrosis.

As new nanomaterials are developed, it is important to consider potential mechanisms of toxicity. Nanomaterials have the increased potential to cross biological barriers and obtain access to tissues and cells as a result of their physicochemical properties. As novel properties are introduced into nanomaterials resulting in new interactions with biological systems, it is possible that new mechanisms of injury and toxicological paradigms might emerge [200]. A further understanding of how nanomaterials interact with biological systems may provide better methods to engineer nanomaterials to minimize toxicity [20].

Mass transport

Efficient delivery of nanotherapeutics is another challenge encountered in regards to nanomaterials. The small size of nanoparticles may result in acceleration or delay in their intended action. They may also accumulate non-specifically in certain tissues after administration. Enormous efforts have been expended towards achieving targeted delivery through modification of nanoparticles with antibodies, small molecules, aptamers and/or peptides. However, the biodistribution of nanotherapeutical agents is primarily governed by their ability to negotiate through biological barriers including the mononuclear phagocyte system (MPS), endothelial/epithelial membranes, complex networks of blood vessels, and abnormal blood flow. In addition, drug delivery is further inhibited by barriers such as enzymatic degradation and molecular/ionic efflux pumps that expel drugs from target cells. A full understanding of the interactions between nanomaterials and biological systems will open the door to rational design of nanomedicines and hence improve their biodistribution.

Complexity of nanopharmaceuticals, characterization, stability and storage

To design therapeutics and diagnostics that are functional for personalized use, multiple components will be integrated into a single nanomaterial, requiring multiple steps such as chemical synthesis, formulation and purification. Those procedures will inevitably lower the yield and increase the production cost. In addition, scale-up and manufacturing under current good manufacturing practice (cGMP) will be challenging. In general, multifunctional nanotherapeutics have more variables within their physicochemical properties, which make it more difficult to predict the fate and action after administration. The characterization of nanotherapeutic agents also poses a challenge to manufacturers as well as regulators in terms of chemical, physical, magnetic, optical and biological properties. It would be difficult to monitor a wide range of physicochemical parameters including composition, structure, shape, size, size distribution, concentration, agglomeration, surface functionality, porosity, surface area, surface charge, and surface specification after nanotherapeutic agents are administered.

Stability and storage are also hurdles that must be addressed for clinical practice. For example, biodegradable polymers have been widely used as nanotherapeutic carriers. Depending on their chemical and morphological properties, a polymer will start degrading after nanoparticle formulation in aqueous/organic solvents, which usually results in a change in physicochemical properties (such as agglomeration, particle size, surface charge, drug loading, drug release profile), and can in turn affect the performance in vivo. As such, storage conditions may be critical to the shelf life of nanotherapeutics. For example, the measurement result of nanoparticle size, surface charge, polymer degradation rate and drug release profile may be quite different when nanotherapeutics are stored in deionized water, as opposed to phosphate buffered saline (PBS) or human blood serum.

Limitations and obstacles of personalized nanomedicine

While personalized nanomedicine holds much promise, there are also many challenges associated with it that need to be overcome in order for it to reach its full potential. Manipulating materials at the nanoscale level is difficult and complex due to novel nanoscale interactions, forces and effects that can complicate the reliability, predictability and utility of nanomedical products. Moreover, the potential risks of nanomedicine products and the uncertainties associated with those risks make it difficult to design and obtain consent in clinical trials to assess the clinical utility of such products.

Regulatory approval of nanomedicine products may present another major obstacle. Personalized treatment strategies are inherently not designed to be safe and efficacious for a population, but rather for an individual. Due to the complexity and differences among individual patients in terms of therapeutic response, clinical outcome, genetic profile and many other factors, it is inconceivable to evaluate and approve an exponentially large combinatorial library of possible nanoparticle configurations with various sizes, shapes, surface modifications and therapeutic payloads, especially when considering the long time and high cost associated with the development of an average therapeutic. On the other hand, as the nanomaterials involved in personalized medical applications become more advanced and multifunctional, they may increasingly challenge and eventually invalidate traditional regulatory categories and criteria. Thus, regulatory reform is necessary to facilitate the translation of nano-based medical products into clinical use. It will be critical for the Food and Drug Administration (FDA) to make adjustments and additional requirements to provide predictable and well-defined evaluation pathways for nanomedicine products, and to adapt regulatory requirements when appropriate to keep pace with rapidly emerging nanomaterials and nanotechnologies.

The incorporation of nanomaterials and nanotechnology into personalized medicine also brings up ethical issues. Nanodiagnostics and genetic testing offer the opportunity to collect more personal data on patients than ever before [220]. In particular, the use of point-of-care nanodevices that may bypass a health care professional will have a large impact on mass collection of personal data. This large volume of molecular-level data collected by such nanodevices will challenge the health care system in terms of storage and handling as well as privacy issues, and may raise questions for patients who will receive a torrent of medical information that will inevitably contain false positive and other misleading data [187].

The advances in nanomaterials and nanobiotechnology will play an important role in the development of cutting-edge diagnostic and therapeutic tools, which are an essential component of personalized medicine. While nanomedicine products face safety, scientific, regulatory and ethical issues, personalized medicine also encounters challenges and obstacles. A major obstacle with personalized approaches such as genetic testing is heterogeneity. A recent study demonstrated that a tumor’s genetic makeup can vary significantly within a single tumor [221]. The study showed that, within a single tumor, about 2/3 of the mutations found in a single biopsy was not uniformly detected throughout all the sampled regions of the same patient’s tumors. These results elucidated that a single biopsy cannot be considered representative of the landscape of genetic abnormalities in a tumor and that current practices may miss important genetic mutations that could affect the treatment of the disease [222]. Moreover, there were significant differences between mutations in the original tumor and the site of metastasis. The tumor discovered at diagnosis may be very different from the tumor that is growing or exposed to different treatments. However, getting additional biopsies from patients at different stages could be costly and inconvenient for patients. These findings represent a significant challenge for personalized medicine, as the use of genetic testing to direct therapy may be more complex than currently thought.

Economic considerations

The economical conundrums behind the advance of personalized nanomedicine are intricate. On the one hand, given the important resources devoted to the development of complex nanomaterial systems, the choice to focus only on the treatment of a subset of the population (i.e., HER-2 positive breast cancer patients) might be a difficult one to make. The aforementioned risks and challenges associated with the design of nanomaterial remain similar whether it is to treat all patients suffering from cancer or just a cohort showing a specific mutation. Therefore, the financial gain-to-risk ratio strongly leans towards applications which benefit larger populations. On the other hand, the proof of efficacy needed to obtain regulatory approval might be easier to obtain with a system rationally designed for a specific subpopulation where the prognosis with standard treatment is particularly grim. The evaluation of therapeutic candidates in patients that are more likely to benefit from it might speed up clinical trials and facilitate regulatory approval of the nanomaterial.

In this context, what makes nanomaterials remarkably appealing are their versatility and the ability to transfer the efforts dedicated to the development of one platform to other applications. The example of the CLION system, where the imaging platform was translated from oncology to cardiovascular applications was mentioned in section 3.2 [175178], but others also exist. For example, liposomes similar to the commercially-available doxorubicin liposomal formulations were recently proposed to act as scavenging nanomaterials for drug detoxification [223, 224]. Similarly, 2-hydroxypropyl-β-cyclodextrin, an excipient which forms nanosized complexes with multiple drugs, was shown to overcome cholesterol metabolism dysfunction in Niemann-Pick Type C [225, 226]. It was approved in 2011 for the intravenous and intrathecal treatment of this very rare LSD.

Finally, the development of treatments for orphan or “niche” diseases might provide attractive entryways to the clinic for nanomaterials. The favorable benefit-to-risk ratio expressly encountered in disorders for which no current treatment exist can prove an efficient way of showing the feasibility of an approach as well as the tolerability and safety of a novel material. In this perspective, scientists at the Children’s Hospital of Philadelphia have invested tremendous efforts in developing an adenovirus-based treatment for Leber Congenital Amaurosis (LCA), a very rare degenerative disease which irremediably leads to blindness [227229]. This gene delivery vector, which is now in phase II/III for LCA, was developed in parallel with an analogous formulation containing encoding DNA for the human coagulation factor IX, for the treatment of hemophilia B [230]. These examples, showcasing the versatility of drug delivery systems, offer strong support to the future contribution of nanomedicine to personalized medicine.


In summary, the application of nanomaterials in the realm of medicine has demonstrated tremendous potential from early diagnosis of disease to the development of highly effective targeted therapeutics. As our understanding of health and disease become more refined at the molecular level, the potential of nanomaterials to address the biological complexities of diseases will increase. Likewise, opportunities to develop patient- and disease-specific therapeutics or diagnostic modalities will emerge.

Contemporary chemistry and material science enable the fabrication of a virtually infinite library of nanomaterials. In the near future, these materials will be engineered to efficiently optimize interactions with biological systems for a range of medical applications. For the purpose of targeted therapy and diagnostic imaging, nanocarriers should possess improved stability, extended circulation half-life, favorable biodistribution profiles, lower immunotoxicity as well as targeting to specific tissues, cells and subcellular organelles. Proper ligands will also be chosen based on differential expression of molecular markers on diseased cells to produce patient-specific nanomedicines. When used for detection and diagnosis, nanomaterials should be engineered to avoid non-specific protein absorption and specifically recognize the targets of interest with high affinity. In this context, an in-depth understanding and thorough investigation of how nanomaterials interact with biological structures is required. In order to promote the development of nanomedicines into clinically feasible therapies, there is an urgent need for complete characterization of nanomaterial interactions with biological milieus that drive possible toxicological responses. Medical products must be demonstrated to not only be effective but also safe before they are approved for patient use. Some experimental studies have indicated that engineered nanomaterials could exhibit unique toxicological properties in cell culture and in animal models that may not be predicted from the toxicological assessment of the bulk version of the same materials. To establish a database and appropriated standardized protocols for toxicity assessment, the mechanism of nanomaterial-induced toxicity must be fully explored and nanomaterials must be investigated in vitro and in vivo (e.g., absorption, distribution, metabolism, excretion and toxicological studies) on a particle-by-particle basis.

In parallel, the concept of personalized medicine is also particularly appealing from the perspective of optimizing treatments for an individual patient. Nevertheless, this is a nascent field that has yet to reach its full potential. A potential error may be to succumb to over-enthusiasm and adopt personalized therapeutic practices without strong evidence that personalized treatment is superior to conventional approaches. Even in the field of antibody-based targeted anticancer treatments, which benefited from a head-start in individualized therapies, each clinical or genomic study brings new understanding of the intricate phenomena involved in treating the disease [231]. The understanding of all genomic components of complex diseases like cancer is still unraveling. One should therefore be careful before jumping to conclusions in identifying a particular biomarker as the new ubiquitous target that will eradicate the disease once and for all.

Although significant challenges exist, including regulatory issues and scientific challenges associated with manufacturing nanomedical products, the development and deployment of personalized nanomedicines holds enormous promise for the future treatment of complex diseases. Some nanomedicine products are already in clinical trials, and many others are in various phases of preclinical development. Critical and rational assessment of clinical needs coupled with an improved understanding of physicochemical parameters of nanomaterials that define their effects on the biological system will foster the development of efficient and safe nanomedicine. It is therefore practical to envision a future translation of personalized nanomedicine to the bedside.

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EU regulatory changes adapted from the Regulatory blog of Dr. Melvin Crasto

New EU GMP Annex 15 Revision published – Valid as of 1 October 2015.

Reporter Stephen J. Williams, Ph.D.


courtesy of Dr. Melvin Crasto’s blog

EU and FDA offer new guidelines in recently published drafts on GMP (Good Manufacturing Procedures) and validation processes incorporating new manufacturing technologies throughout the drug developing and manufacturing life cycle.

The clear focus on user requirements in the area of qualification will also have an impact on equipment suppliers. Process validation will become a difficult task in the future. With 3 different approaches there are clear differences to the US. However, the ongoing process verification means additional effort and is now comparable to the US requirements.

This enhanced “across-the-sea” cooperation between FDA and EU is seeming to become the norm in the drug development world as once seemingly distinct lines separating US and EU companies have become blurred.

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Protecting Your Biotech IP and Market Strategy: Notes from Life Sciences Collaborative 2015 Meeting


Protecting Your Biotech IP and Market Strategy: Notes from Life Sciences Collaborative 2015 Meeting

Achievement Beyond Regulatory Approval – Design for Commercial Success

philly2nightStephen J. Williams, Ph.D.: Reporter

The Mid-Atlantic group Life Sciences Collaborative, a select group of industry veterans and executives from the pharmaceutical, biotechnology, and medical device sectors whose mission is to increase the success of emerging life sciences businesses in the Mid-Atlantic region through networking, education, training and mentorship, met Tuesday March 3, 2015 at the University of the Sciences in Philadelphia (USP) to discuss post-approval regulatory issues and concerns such as designing strong patent protection, developing strategies for insurance reimbursement, and securing financing for any stage of a business.

The meeting was divided into three panel discussions and keynote speech:

  1. Panel 1: Design for Market Protection– Intellectual Property Strategy Planning
  2. Panel 2: Design for Market Success– Commercial Strategy Planning
  3. Panel 3: Design for Investment– Financing Each Stage
  4. Keynote Speaker: Robert Radie, President & CEO Egalet Corporation

Below are Notes from each PANEL Discussion:

For more information about the Life Sciences Collaborative SEE


Or On Facebook

Or On Twitter @LSCollaborative

Panel 1: Design for Market Protection; Intellectual Property Strategy Planning

Take-home Message: Developing a very strong Intellectual Property (IP) portfolio and strategy for a startup is CRITICALLY IMPORTANT for its long-term success. Potential investors, partners, and acquirers will focus on the strength of a startup’s IP so important to take advantage of the legal services available. Do your DUE DIGILENCE.


John F. Ritter, J.D.., MBA; Director Office Tech. Licensing Princeton University

Cozette McAvoy; Senior Attorney Novartis Oncology Pharma Patents

Ryan O’Donnell; Partner Volpe & Koenig

Panel Moderator: Dipanjan “DJ” Nag, PhD, MBA, CLP, RTTP; President CEO IP Shaktl, LLC


Dr. Nag:

  • Sometimes IP can be a double edged sword; e.g. Herbert Boyer with Paul Berg and Stanley Cohen credited with developing recombinant technology but they did not keep the IP strict and opened the door for a biotech revolution (see nice review from Chemical Heritage Foundation).
  • Naked patent licenses are most profitable when try to sell IP

John Ritter: Mr. Ritter gave Princeton University’s perspective on developing and promoting a university-based IP portfolio.

  • 30-40% of Princeton’s IP portfolio is related to life sciences
  • Universities will prefer to seek provisional patent status as a quicker process and allows for publication
  • Princeton will work closely with investigators to walk them through process – Very Important to have support system in place INCLUDING helping investigators and early startups establish a STRONG startup MANAGEMENT TEAM, and making important introductions to and DEVELOPING RELATIONSHIOPS with investors, angels
  • Good to cast a wide net when looking at early development partners like pharma
  • Good example of university which takes active role in developing startups is University of Pennsylvania’s Penn UPstart program.
  • Last 2 years many universities filing patents for startups as a micro-entity

Comment from attendee: Universities are not using enough of their endowments for purpose of startups. Princeton only using $500,00 for accelerator program.

Cozette McAvoy: Mrs. McAvoy talked about monetizing your IP from an industry perspective

  • Industry now is looking at “indirect monetization” of their and others IP portfolio. Indirect monetization refers to unlocking the “indirect value” of intellectual property; for example research tools, processes, which may or may not be related to a tangible product.
  • Good to make a contractual bundle of IP – “days of the $million check is gone”
  • Big companies like big pharma looks to PR (press relation) buzz surrounding new technology, products SO IMPORTANT FOR STARTUP TO FOCUS ON YOUR PR

Ryan O’Donnell: talked about how life science IP has changed especially due to America Invests Act

  • Need to develop a GLOBAL IP strategy so whether drug or device can market in multiple countries
  • Diagnostics and genes not patentable now – Major shift in patent strategy
  • Companies like Unified Patents can protect you against the patent trolls – if patent threatened by patent troll (patent assertion entity) will file a petition with the USPTO (US Patent Office) requesting institution of inter partes review (IPR); this may cost $40,000 BUT WELL WORTH the money – BE PROACTIVE about your patents and IP

Panel 2: Design for Market Success; Commercial Strategy Planning

Take-home Message: Commercial strategy development is defined market facing data, reimbursement strategies and commercial planning that inform labeling requirements, clinical study designs, healthcare economic outcomes and pricing targets. Clarity from payers is extremely important to develop any market strategy. Develop this strategy early and seek advice from payers.


David Blaszczak; Founder, Precipio Health Strategies

Terri Bernacchi, PharmD, MBA; Founder & President Cambria Health Advisory Professionals

Paul Firuta; President US Commercial Operations, NPS Pharma


Panel Moderator: Matt Cabrey; Executive Director, Select Greater Philadelphia



David Blaszczak:

  • Commercial payers are bundling payment: most important to get clarity from these payers
  • Payers are using clinical trials to alter marketing (labeling) so IMPORTANT to BUILD LABEL in early clinical trial phases (phase I or II)
  • When in early phases of small company best now to team or partner with a Medicare or PBM (pharmacy benefit manager) and payers to help develop and spot tier1 and tier 2 companies in their area

Terri Bernacchi:

  • Building relationship with the payer is very important but firms like hers will also look to patients and advocacy groups to see how they respond to a given therapy and decrease the price risk by bundling
  • Value-based contracting with manufacturers can save patient and payer $$
  • As most PBMs formularies are 80% generics goal is how to make money off of generics
  • Patent extension would have greatest impact on price, value

Paul Firuta:

  • NPS Pharma developing a pharmacy benefit program for orphan diseases
  • How you pay depends on mix of Medicare, private payers now
  • Most important change which could affect price is change in compliance regulations

Panel 3: Design for Investment; Financing Each Stage

Take-home Message: VC is a personal relationship so spend time making those relationships. Do your preparation on your value and your market. Look to non-VC avenues: they are out there.


Ting Pau Oei; Managing Director, Easton Capital (NYC)

Manya Deehr; CEO & Founder, Pediva Therapeutics

Sanjoy Dutta, PhD; Assistant VP, Translational Devel. & Intl. Res., Juvenile Diabetes Research Foundation


Panel Moderator: Shahram Hejazi, PhD; Venture Partner, BioAdvance

  • In 2000 his experience finding 1st capital was what are your assets; now has changed to value


Ting Pau Oei:

  • Your very 1st capital is all about VALUE– so plan where you add value
  • Venture Capital is a PERSONAL RELATIONSHIP
  • 1) you need the management team, 2) be able to communicate effectively                  (Powerpoint, elevator pitch, business plan) and #1 and #2 will get you important 2nd Venture Capital meeting; VC’s don’t decide anything in 1st meeting
  • VC’s don’t normally do a good job of premarket valuation or premarket due diligence but know post market valuation well
  • Best advice: show some phase 2 milestones and VC will knock on your door

Manya Deehr:

  • Investment is more niche oriented so find your niche investors
  • Define your product first and then match the investors
  • Biggest failure she has experienced: companies that go out too early looking for capital

Dr. Dutta: funding from a non-profit patient advocacy group perspective

  • Your First Capital: find alliances which can help you get out of “valley of death
  • Develop a targeted product and patient treatment profile
  • Non-profit groups ask three questions:

1) what is the value to patients (non-profits want to partner)

2) what is your timeline (we can wait longer than VC; for example Cystic Fibrosis Foundation waited long time but got great returns for their patients with Kalydeco™)

3) when can we see return

  • Long-term market projections are the knowledge gaps that startups have (the landscape) and startups don’t have all the competitive intelligence
  • Have a plan B every step of the way

Other posts on this site related to Philadelphia Biotech, Startup Funding, Payer Issues, and Intellectual Property Issues include:

PCCI’s 7th Annual Roundtable “Crowdfunding for Life Sciences: A Bridge Over Troubled Waters?” May 12 2014 Embassy Suites Hotel, Chesterbrook PA 6:00-9:30 PM
The Vibrant Philly Biotech Scene: Focus on KannaLife Sciences and the Discipline and Potential of Pharmacognosy
The Vibrant Philly Biotech Scene: Focus on Computer-Aided Drug Design and Gfree Bio, LLC
The Vibrant Philly Biotech Scene: Focus on Vaccines and Philimmune, LLC
The Bioscience Crowdfunding Environment: The Bigger Better VC?
Foundations as a Funding Source
Venture Capital Funding in the Life Sciences: Phase4 Ventures – A Case Study
10 heart-focused apps & devices are crowdfunding for American Heart Association’s open innovation challenge
Funding, Deals & Partnerships
Medicare Panel Punts on Best Tx for Carotid Plaque
9:15AM–2:00PM, January 27, 2015 – Regulatory & Reimbursement Frameworks for Molecular Testing, LIVE @Silicon Valley 2015 Personalized Medicine World Conference, Mountain View, CA
FDA Commissioner, Dr. Margaret A. Hamburg on HealthCare for 310Million Americans and the Role of Personalized Medicine
Biosimilars: Intellectual Property Creation and Protection by Pioneer and by Biosimilar Manufacturers
Litigation on the Way: Broad Institute Gets Patent on Revolutionary Gene-Editing Method
The Patents for CRISPR, the DNA editing technology as the Biggest Biotech Discovery of the Century



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The Vibrant Philly Biotech Scene: Focus on KannaLife Sciences and the Discipline and Potential of Pharmacognosy

Curator and Interviewer: Stephen J. Williams, Ph.D.


philly2nightThis post is the third in a series of posts highlighting interviews with Philadelphia area biotech startup CEO’s and show how a vibrant biotech startup scene is evolving in the city as well as the Delaware Valley area. Philadelphia has been home to some of the nation’s oldest biotechs including Cephalon, Centocor, hundreds of spinouts from a multitude of universities as well as home of the first cloned animal (a frog), the first transgenic mouse, and Nobel laureates in the field of molecular biology and genetics. Although some recent disheartening news about the fall in rankings of Philadelphia as a biotech hub and recent remarks by CEO’s of former area companies has dominated the news, biotech incubators like the University City Science Center and Bucks County Biotechnology Center as well as a reinvigorated investment community (like PCCI and MABA) are bringing Philadelphia back. And although much work is needed to bring the Philadelphia area back to its former glory days (including political will at the state level) there are many bright spots such as the innovative young companies as outlined in these posts.

In today’s post, I had the opportunity to talk with both Dr. William Kinney, Chief Scientific Officer and Thoma Kikis, Founder/CMO of KannaLife Sciences based in the Pennsylvania Biotech Center of Bucks County.   KannaLifeSciences, although highlighted in national media reports and Headline news (HLN TV)for their work on cannabis-derived compounds, is a phyto-medical company focused on the discipline surrounding pharmacognosy, the branch of pharmacology dealing with natural drugs and their constituents.

Below is the interview with Dr. Kinney and Mr. Kikis of KannaLife Sciences and Leaders in Pharmaceutical Business Intelligence (LPBI)


PA Biotech Questions answered by Dr. William Kinney, Chief Scientific Officer of KannaLife Sciences



LPBI: Your parent company   is based in New York. Why did you choose the Bucks County Pennsylvania Biotechnology Center?


Dr. Kinney: The Bucks County Pennsylvania Biotechnology Center has several aspects that were attractive to us.  They have a rich talent pool of pharmaceutically trained medicinal chemists, an NIH trained CNS pharmacologist,  a scientific focus on liver disease, and a premier natural product collection.


LBPI: The Blumberg Institute and Natural Products Discovery Institute has acquired a massive phytochemical library. How does this resource benefit the present and future plans for KannaLife?


Dr. Kinney: KannaLife is actively mining this collection for new sources of neuroprotective agents and is in the process of characterizing the active components of a specific biologically active plant extract.  Jason Clement of the NPDI has taken a lead on these scientific studies and is on our Advisory Board. 


LPBI: Was the state of Pennsylvania and local industry groups support KannaLife’s move into the Doylestown incubator?


Dr. Kinney: The move was not State influenced by state or industry groups. 


LPBI: Has the partnership with Ben Franklin Partners and the Center provided you with investment opportunities?


Dr. Kinney: Ben Franklin Partners has not yet been consulted as a source of capital.


LPBI: The discipline of pharmacognosy, although over a century old, has relied on individual investigators and mainly academic laboratories to make initial discoveries on medicinal uses of natural products. Although there have been many great successes (taxol, many antibiotics, glycosides, etc.) many big pharmaceutical companies have abandoned this strategy considering it a slow, innefective process. Given the access you have to the chemical library there at Buck County Technology Center, the potential you had identified with cannabanoids in diseases related to oxidative stress, how can KannaLife enhance the efficiency of finding therapeutic and potential preventive uses for natural products?


Dr. Kinney: KannaLife has the opportunity to improve upon natural molecules that have shown medically uses, but have limitations related to safety and bioavailability. By applying industry standard medicinal chemistry optimization and assay methods, progress is being made in improving upon nature.  In addition KannaLife has access to one of the most commercially successful natural products scientists and collections in the industry.


LPBI: How does the clinical & regulatory experience in the Philadelphia area help a company like Kannalife?


Dr. Kinney: Within the region, KannaLife has access to professionals in all areas of drug development either by hiring displaced professionals or partnering with regional contract research organizations.


LPBI  You are focusing on an interesting mechanism of action (oxidative stress) and find your direction appealing (find compounds to reverse this, determine relevant disease states {like HCE} then screen these compounds in those disease models {in hippocampal slices}).  As oxidative stress is related to many diseases are you trying to develop your natural products as preventative strategies, even though those type of clinical trials usually require massive numbers of trial participants or are you looking to partner with a larger company to do this?


Dr. Kinney: Our strategy is to initially pursue Hepatic Encephalophy (HE) as the lead orphan disease indication and then partner with other organizations to broaden into other areas that would benefit from a neuroprotective agent.  It is expected the HE will be responsive to an acute treatment regimen.   We are pursuing both natural products and new chemical entities for this development path.



General Questions answered by Thoma Kikis, Founder/CMO of KannaLife Sciences


LPBI: How did KannaLife get the patent from the National Institutes of Health?


My name is Thoma Kikis I’m the co-founder of KannaLife Sciences. In 2010, my partner Dean Petkanas and I founded KannaLife and we set course applying for the exclusive license of the ‘507 patent held by the US Government Health and Human Services and National Institutes of Health (NIH). We spent close to 2 years working on acquiring an exclusive license from NIH to commercially develop Patent 6,630,507 “Cannabinoids as Antioxidants and Neuroprotectants.” In 2012, we were granted exclusivity from NIH to develop a treatment for a disease called Hepatic Encephalopathy (HE), a brain liver disease that stems from cirrhosis.


Cannabinoids are the chemicals that compose the Cannabis plant. There are over 85 known isolated Cannabinoids in Cannabis. The cannabis plant is a repository for chemicals, there are over 400 chemicals in the entire plant. We are currently working on non-psychoactive cannabinoids, cannabidiol being at the forefront.


As we started our work on HE and saw promising results in the area of neuroprotection we sought out another license from the NIH on the same patent to treat CTE (Chronic Traumatic Encephalopathy), in August of 2014 we were granted the additional license. CTE is a concussion related traumatic brain disease with long term effects mostly suffered by contact sports players including football, hockey, soccer, lacrosse, boxing and active military soldiers.


To date we are the only license holders of the US Government held patent on cannabinoids.



LPBI: How long has this project been going on?


We have been working on the overall project since 2010. We first started work on early research for CTE in early-2013.



LPBI: Tell me about the project. What are the goals?


Our focus has always been on treating diseases that effect the Brain. Currently we are looking for solutions in therapeutic agents designed to reduce oxidative stress, and act as immuno-modulators and neuroprotectants.


KannaLife has an overall commitment to discover and understand new phytochemicals. This diversification of scientific and commercial interests strongly indicates a balanced and thoughtful approach to our goals of providing standardized, safer and more effective medicines in a socially responsible way.


Currently our research has focused on the non-psychoactive cannabidiol (CBD). Exploring the appropriate uses and limitations and improving its safety and Metered Dosing. CBD has a limited therapeutic window and poor bioavailability upon oral dosing, making delivery of a consistent therapeutic dose challenging. We are also developing new CBD-like molecules to overcome these limitations and evaluating new phytochemicals from non-regulated plants.


KannaLife’s research is led by experienced pharmaceutically trained professionals; Our Scientific team out of the Pennsylvania Biotechnology Center is led by Dr. William Kinney and Dr. Douglas Brenneman both with decades of experience in pharmaceutical R&D.



LPBI: How do cannabinoids help neurological damage? -What sort of neurological damage do they help?


Cannabinoids and specifically cannabidiol work to relieve oxidative stress, and act as immuno-modulators and neuroprotectants.


So far our pre-clinical results show that cannabidiol is a good candidate as a neuroprotectant as the patent attests to. Our current studies have been to protect neuronal cells from toxicity. For HE we have been looking specifically at ammonia and ethanol toxicity.



– How did it go from treating general neurological damage to treating CTE? Is there any proof yet that cannabinoids can help prevent CTE? What proof?


We started examining toxicity first with ammonia and ethanol in HE and then posed the question; If CBD is a neuroprotectant against toxicity then we need to examine what it can do for other toxins. We looked at CTE and the toxin that causes it, tau. We just acquired the license in August from the NIH for CTE and are beginning our pre-clinical work in the area of CTE now with Dr. Ron Tuma and Dr. Sara Jane Ward at Temple University in Philadelphia.



LPBI: How long until a treatment could be ready? What’s the timeline?


We will have research findings in the coming year. We plan on filing an IND (Investigational New Drug application) with the FDA for CBD and our molecules in 2015 for HE and file for CTE once our studies are done.



LPBI: What other groups are you working with regarding CTE?


We are getting good support from former NFL players who want solutions to the problem of concussions and CTE. This is a very frightening topic for many players, especially with the controversy and lawsuits surrounding it. I have personally spoken to several former NFL players, some who have CTE and many are frightened at what the future holds.


We enrolled a former player, Marvin Washington. Marvin was an 11 year NFL vet with NY Jets, SF 49ers and won a SuperBowl on the 1998 Denver Broncos. He has been leading the charge on KannaLife’s behalf to raise awareness to the potential solution for CTE.


We tried approaching the NFL in 2013 but they didn’t want to meet. I can understand that they don’t want to take a position. But ultimately, they’re going to have to make a decision and look into different research to treat concussions. They have already given the NIH $30 Million for research into football related injuries and we hold a license with the NIH, so we wanted to have a discussion. But currently cannabinoids are part of their substance abuse policy connected to marijuana. Our message to the NFL is that they need to lead the science, not follow it.


Can you imagine the NFL’s stance on marijuana treating concussions and CTE? These are topics they don’t want to touch but will have to at some point.


LPBI: Thank you both Dr. Kinney and Mr. Kikis.


Please look for future posts in this series on the Philly Biotech Scene on this site

Also, if you would like your Philadelphia biotech startup to be highlighted in this series please contact me or at: or @StephenJWillia2  or @pharma_BI.

Our site is read by ~ thousand international readers DAILY and thousands of Twitter followers including venture capital.


Other posts on this site in this VIBRANT PHILLY BIOTECH SCENE SERIES OR referring to PHILADELPHIA BIOTECH include:

The Vibrant Philly Biotech Scene: Focus on Computer-Aided Drug Design and Gfree Bio, LLC

RAbD Biotech Presents at 1st Pitch Life Sciences-Philadelphia

The Vibrant Philly Biotech Scene: Focus on Vaccines and Philimmune, LLC

What VCs Think about Your Pitch? Panel Summary of 1st Pitch Life Science Philly

1st Pitch Life Science- Philadelphia- What VCs Really Think of your Pitch

LytPhage Presents at 1st Pitch Life Sciences-Philadelphia

Hastke Inc. Presents at 1st Pitch Life Sciences-Philadelphia

PCCI’s 7th Annual Roundtable “Crowdfunding for Life Sciences: A Bridge Over Troubled Waters?” May 12 2014 Embassy Suites Hotel, Chesterbrook PA 6:00-9:30 PM

Pfizer Cambridge Collaborative Innovation Events: ‘The Role of Innovation Districts in Metropolitan Areas to Drive the Global an | Basecamp Business

Mapping the Universe of Pharmaceutical Business Intelligence: The Model developed by LPBI and the Model of Best Practices LLC



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