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Archive for the ‘BioPrinting in Regenerative Medicine’ Category

Immunoediting can be a constant defense in the cancer landscape


Reporter and Curator: Dr. Sudipta Saha, Ph.D.

 

There are many considerations in the cancer immunoediting landscape of defense and regulation in the cancer hallmark biology. The cancer hallmark biology in concert with key controls of the HLA compatibility affinity mechanisms are pivotal in architecting a unique patient-centric therapeutic application. Selection of random immune products including neoantigens, antigens, antibodies and other vital immune elements creates a high level of uncertainty and risk of undesirable immune reactions. Immunoediting is a constant process. The human innate and adaptive forces can either trigger favorable or unfavorable immunoediting features. Cancer is a multi-disease entity. There are multi-factorial initiators in a certain disease process. Namely, environmental exposures, viral and / or microbiome exposure disequilibrium, direct harm to DNA, poor immune adaptability, inherent risk and an individual’s own vibration rhythm in life.

 

When a human single cell is crippled (Deranged DNA) with mixed up molecular behavior that is the initiator of the problem. A once normal cell now transitioned into full threatening molecular time bomb. In the modeling and creation of a tumor it all begins with the singular molecular crisis and crippling of a normal human cell. At this point it is either chop suey (mixed bit responses) or a productive defensive and regulation response and posture of the immune system. Mixed bits of normal DNA, cancer-laden DNA, circulating tumor DNA, circulating normal cells, circulating tumor cells, circulating immune defense cells, circulating immune inflammatory cells forming a moiety of normal and a moiety of mess. The challenge is to scavenge the mess and amplify the normal.

 

Immunoediting is a primary push-button feature that is definitely required to be hit when it comes to initiating immune defenses against cancer and an adaptation in favor of regression. As mentioned before that the tumor microenvironment is a “mixed bit” moiety, which includes elements of the immune system that can defend against circulating cancer cells and tumor growth. Personalized (Precision-Based) cancer vaccines must become the primary form of treatment in this case. Current treatment regimens in conventional therapy destroy immune defenses and regulation and create more serious complications observed in tumor progression, metastasis and survival. Commonly resistance to chemotherapeutic agents is observed. These personalized treatments will be developed in concert with cancer hallmark analytics and immunocentrics affinity and selection mapping. This mapping will demonstrate molecular pathway interface and HLA compatibility and adaptation with patientcentricity.

References:

 

https://www.linkedin.com/pulse/immunoediting-cancer-landscape-john-catanzaro/

 

https://www.cell.com/cell/fulltext/S0092-8674(16)31609-9

 

https://www.researchgate.net/publication/309432057_Circulating_tumor_cell_clusters_What_we_know_and_what_we_expect_Review

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4190561/

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5840207/

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5593672/

 

https://www.frontiersin.org/articles/10.3389/fimmu.2018.00414/full

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5593672/

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4190561/

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4388310/

 

https://www.linkedin.com/pulse/cancer-hallmark-analytics-omics-data-pathway-studio-review-catanzaro/

 

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3D Print Shape-Shifting Smart Gel

Reporter: Irina Robu, PhD

Hydrogel scaffolds that mimic the native extracellular matrix (ECM) environment play a crucial role in tissue engineering and they are ubiquitously in our lives, including in contact lenses, diapers and the human body.

Researchers at Rutgers have invented a printing method for a smart gel that can be used to create materials for transporting small molecules like drugs to human organs. The approach includes printing a 3D object with a hydrogel that changes shape over time when temperature changes. The potential of the smart hydrogels could be to create a new are of soft robotics and enable new applications in flexible sensors and actuators, biomedical devices and platforms or scaffolds for cells to grow.

Rutgers engineers operated with a hydrogel that has been in use for decades in devices that generate motion and biomedical applications such as scaffolds for cells to grow on. The engineers learned how to precisely control hydrogel growth and shrinkage. In temperatures below 32 degrees Celsius, the hydrogel absorbs more water and swells in size. When temperatures exceed 32 degrees Celsius, the hydrogel begins to expel water and shrinks, the study showed.

According to the Rutgers engineers, the objects they can produce with the hydrogel range from the width of a human hair to several millimeters long. The engineers also showed that they can grow one area of a 3D-printed object by changing temperatures.

Source

https://news.rutgers.edu/rutgers-engineers-3d-print-shape-shifting-smart-gel/20180131

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New Liver Tissue Implants Showing Potential

Reporter: Irina Robu,PhD

To develop new tissues, researchers at the Medical Research Council Center for Regenerative Medicine at the University of Edinburgh have found that stem cells transformed into 3-D liver tissue can support liver function when implanted into the mice suffering with a liver disease.

The scientists stimulated human embryonic stem cells and induced pluripotent stem cells to mature pluripotent stem cells into liver cells, hepatocytes. Hepatocytes are the chief functional cells of the liver and perform an astonishing number of metabolic, endocrine and secretory functions. Hepatocytes are exceptionally active in synthesis of protein and lipids for export. The cells are grown in 3-D conditions as small spheres for over a year. However, keeping the stem cells as liver cells for a long time is very difficult, because the viability of hepatocytes decreases in-vitro conditions.

Succeeding the discovery, the team up with materials chemists and engineers to detect appropriate polymers that have already been approved for human use that can be developed into 3-D scaffolds. The best material to use a biodegradable polyester, called polycaprolactone (PCL).PCL is degraded by hydrolysis of its ester linkages in physiological conditions (such as in the human body) and it is especially interesting for the preparation of long term implantable devices, owing to its degradation which is even slower than that of polylactide. They spun the PCL into microscopic fibers that formed a scaffold one centimeter square and a few millimeters thick.

At the same time, hepatocytes derived from embryonic cells had been grown in culture for 20 days and were then loaded onto the scaffolds and implanted under the skin of mice.Blood vessels successfully grew on the scaffolds with the mice having human liver proteins in their blood, demonstrating that the tissue had successfully integrated with the circulatory system. The scaffolds were not rejected by the animals’ immune systems.

The scientists tested the liver tissue scaffolds in mice with tyrosinaemia,a potentially fatal genetic disorder where the enzymes in the liver that break down the amino acid tyrosine are defective, resulting in the accumulation of toxic metabolic products. The implanted liver tissue aided the mice with tyrosinaemia to break down tyrosine and the mice finally lost less weight, had less buildup of toxins in the blood and exhibited fewer signs of liver damage than the control group that received empty scaffolds.

According to Rob Buckle, PhD, Chief Science Officer at the MRC, “Showing that such stem cell-derived tissue is able to reproduce aspects of liver function in the lab also offers real potential to improve the testing of new drugs where more accurate models of human tissue are needed”. It is believed that the discovery could be the next step towards harnessing stem cell reprogramming technologies to provide renewable supplies of liver tissue products for transplantation.

SOURCE

https://www.rdmag.com/article/2018/08/new-liver-tissue-implants-showing-promise?et_cid=6438323

 

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3-D Printed Ovaries Produce Healthy Offspring

Reporter: Irina Robu, PhD

 

Each year about 120,000 organs are transplanted from one human being to another and most of the time is a living volunteer. But lack of suitable donors, predominantly means the supply of such organs is inadequate. Countless people consequently die waiting for a transplant which has led researchers to study the question of how to build organs from scratch.

One promising approach is to print them, but “bioprinting” remains largely experimental. Nevertheless, bioprinted tissue is before now being sold for drug testing, and the first transplantable tissues are anticipated to be ready for use in a few years’ time. The first 3D printed organ includes bioprosthetic ovaries which are constructed of 3D printed scaffolds that have immature eggs and have been successful in boosting hormone production and restoring fertility was developed by Teresa K. Woodruff, a reproductive scientist and director of the Women’s Health Research Institute at Feinberg School of Medicine, at Northwestern University, in Illinois.

What sets apart these bioprosthetic ovaries is the architecture of the scaffold. The material is made of gelatin made from broken-down collagen that is safe to humans which is self-supporting and can lead to building multiple layers.

The 3-D printed “scaffold” or “skeleton” is implanted into a female and its pores can be used to optimize how follicles, or immature eggs, get wedged within the scaffold. The scaffold supports the survival of the mouse’s immature egg cells and the cells that produce hormones to boost production. The open construction permits room for the egg cells to mature and ovulate, blood vessels to form within the implant enabling the hormones to circulate and trigger lactation after giving birth. The purpose of this scaffold is to recapitulate how an ovary would function.
The scientists’ only objective for developing the bioprosthetic ovaries was to help reestablish fertility and hormone production in women who have suffered adult cancer treatments and now have bigger risks of infertility and hormone-based developmental issues.

 

SOURCES

Printed human body parts could soon be available for transplant
https://www.economist.com/news/science-and-technology/21715638-how-build-organs-scratch

 

3D printed ovaries produce healthy offspring giving hope to infertile women

http://www.telegraph.co.uk/science/2017/05/16/3d-printed-ovaries-produce-healthy-offspring-giving-hope-infertile/

 

Brave new world: 3D-printed ovaries produce healthy offspring

http://www.naturalnews.com/2017-05-27-brave-new-world-3-d-printed-ovaries-produce-healthy-offspring.html

 

3-D-printed scaffolds restore ovary function in infertile mice

http://www.medicalnewstoday.com/articles/317485.php

 

Our Grandkids May Be Born From 3D-Printed Ovaries

http://gizmodo.com/these-mice-gave-birth-using-3d-printed-ovaries-1795237820

 

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Nanostraws Developed at Stanford Sample a Cell’s Contents without Damage

Reporter: Irina Robu, PhD

Cells within our bodies change over time and divide, with thousands of chemical reactions happening within cell daily. Nicholas Melosh, Associate Professor of Materials Science and Engineering, developed a new, non-destructive system for sampling cells with nanoscale straws which could help uncover mysteries about how cells function.

Currently, cells are sampled via lysing which ruptures the cell membrane which means that it can’t ever be sampled again. The sample system that Dr. Melosh invented banks on, on tiny tubes 600 times smaller than a strand of hair that allow researchers to sample a single cell at a time. The nanostraws penetrate a cell’s outer membrane, without damaging it, and draw out proteins and genetic material from the cell’s salty interior.

The Nanostraw sampling technique, according to Melosh, will knowingly impact our understanding of cell development and could result to much safer and operational medical therapies because the technique allows for long term, non-destructive monitoring. The sampling technique could also inform cancer treatments and answer questions about why some cancer cells are resistant to chemotherapy while others are not. The sampling platform on which the nanostraws are grown is tiny, similar to the size of a gumball. It’s called the Nanostraw Extraction (NEX) sampling system, and it was designed to mimic biology itself.

The goal of developing this technology was to make an impact in medical biology by providing a platform that any lab could build.

SOURCE

http://news.stanford.edu/2017/02/20/minuscule-nanostraws-sample-cells-contents-without-damage

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Topical Solution for Combination Oncology Drug Therapy: Patch that delivers Drug, Gene, and Light-based Therapy to Tumor

Reporter: Aviva Lev-Ari, PhD, RN

 

Self-assembled RNA-triple-helix hydrogel scaffold for microRNA modulation in the tumour microenvironment

Affiliations

  1. Massachusetts Institute of Technology, Institute for Medical Engineering and Science, Harvard-MIT Division for Health Sciences and Technology, Cambridge, Massachusetts 02139, USA
    • João Conde,
    • Nuria Oliva,
    • Mariana Atilano,
    • Hyun Seok Song &
    • Natalie Artzi
  2. School of Engineering and Materials Science, Queen Mary University of London, London E1 4NS, UK
    • João Conde
  3. Grup dEnginyeria de Materials, Institut Químic de Sarrià-Universitat Ramon Llull, Barcelona 08017, Spain
    • Mariana Atilano
  4. Division of Bioconvergence Analysis, Korea Basic Science Institute, Yuseong, Daejeon 169-148, Republic of Korea
    • Hyun Seok Song
  5. Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
    • Natalie Artzi
  6. Department of Medicine, Biomedical Engineering Division, Brigham and Womens Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
    • Natalie Artzi

Contributions

J.C. and N.A. conceived the project and designed the experiments. J.C., N.O., H.S.S. and M.A. performed the experiments, collected and analysed the data. J.C. and N.A. co-wrote the manuscript. All authors discussed the results and reviewed the manuscript.

Nature Materials
15,
353–363
(2016)
doi:10.1038/nmat4497
Received
22 April 2015
Accepted
26 October 2015
Published online
07 December 2015

The therapeutic potential of miRNA (miR) in cancer is limited by the lack of efficient delivery vehicles. Here, we show that a self-assembled dual-colour RNA-triple-helix structure comprising two miRNAs—a miR mimic (tumour suppressor miRNA) and an antagomiR (oncomiR inhibitor)—provides outstanding capability to synergistically abrogate tumours. Conjugation of RNA triple helices to dendrimers allows the formation of stable triplex nanoparticles, which form an RNA-triple-helix adhesive scaffold upon interaction with dextran aldehyde, the latter able to chemically interact and adhere to natural tissue amines in the tumour. We also show that the self-assembled RNA-triple-helix conjugates remain functional in vitro and in vivo, and that they lead to nearly 90% levels of tumour shrinkage two weeks post-gel implantation in a triple-negative breast cancer mouse model. Our findings suggest that the RNA-triple-helix hydrogels can be used as an efficient anticancer platform to locally modulate the expression of endogenous miRs in cancer.

SOURCE

http://www.nature.com/nmat/journal/v15/n3/abs/nmat4497.html#author-information

 

 

Patch that delivers drug, gene, and light-based therapy to tumor sites shows promising results

In mice, device destroyed colorectal tumors and prevented remission after surgery.

Helen Knight | MIT News Office
July 25, 2016

Approximately one in 20 people will develop colorectal cancer in their lifetime, making it the third-most prevalent form of the disease in the U.S. In Europe, it is the second-most common form of cancer.

The most widely used first line of treatment is surgery, but this can result in incomplete removal of the tumor. Cancer cells can be left behind, potentially leading to recurrence and increased risk of metastasis. Indeed, while many patients remain cancer-free for months or even years after surgery, tumors are known to recur in up to 50 percent of cases.

Conventional therapies used to prevent tumors recurring after surgery do not sufficiently differentiate between healthy and cancerous cells, leading to serious side effects.

In a paper published today in the journal Nature Materials, researchers at MIT describe an adhesive patch that can stick to the tumor site, either before or after surgery, to deliver a triple-combination of drug, gene, and photo (light-based) therapy.

Releasing this triple combination therapy locally, at the tumor site, may increase the efficacy of the treatment, according to Natalie Artzi, a principal research scientist at MIT’s Institute for Medical Engineering and Science (IMES) and an assistant professor of medicine at Brigham and Women’s Hospital, who led the research.

The general approach to cancer treatment today is the use of systemic, or whole-body, therapies such as chemotherapy drugs. But the lack of specificity of anticancer drugs means they produce undesired side effects when systemically administered.

What’s more, only a small portion of the drug reaches the tumor site itself, meaning the primary tumor is not treated as effectively as it should be.

Indeed, recent research in mice has found that only 0.7 percent of nanoparticles administered systemically actually found their way to the target tumor.

“This means that we are treating both the source of the cancer — the tumor — and the metastases resulting from that source, in a suboptimal manner,” Artzi says. “That is what prompted us to think a little bit differently, to look at how we can leverage advancements in materials science, and in particular nanotechnology, to treat the primary tumor in a local and sustained manner.”

The researchers have developed a triple-therapy hydrogel patch, which can be used to treat tumors locally. This is particularly effective as it can treat not only the tumor itself but any cells left at the site after surgery, preventing the cancer from recurring or metastasizing in the future.

Firstly, the patch contains gold nanorods, which heat up when near-infrared radiation is applied to the local area. This is used to thermally ablate, or destroy, the tumor.

These nanorods are also equipped with a chemotherapy drug, which is released when they are heated, to target the tumor and its surrounding cells.

Finally, gold nanospheres that do not heat up in response to the near-infrared radiation are used to deliver RNA, or gene therapy to the site, in order to silence an important oncogene in colorectal cancer. Oncogenes are genes that can cause healthy cells to transform into tumor cells.

The researchers envision that a clinician could remove the tumor, and then apply the patch to the inner surface of the colon, to ensure that no cells that are likely to cause cancer recurrence remain at the site. As the patch degrades, it will gradually release the various therapies.

The patch can also serve as a neoadjuvant, a therapy designed to shrink tumors prior to their resection, Artzi says.

When the researchers tested the treatment in mice, they found that in 40 percent of cases where the patch was not applied after tumor removal, the cancer returned.

But when the patch was applied after surgery, the treatment resulted in complete remission.

Indeed, even when the tumor was not removed, the triple-combination therapy alone was enough to destroy it.

The technology is an extraordinary and unprecedented synergy of three concurrent modalities of treatment, according to Mauro Ferrari, president and CEO of the Houston Methodist Research Institute, who was not involved in the research.

“What is particularly intriguing is that by delivering the treatment locally, multimodal therapy may be better than systemic therapy, at least in certain clinical situations,” Ferrari says.

Unlike existing colorectal cancer surgery, this treatment can also be applied in a minimally invasive manner. In the next phase of their work, the researchers hope to move to experiments in larger models, in order to use colonoscopy equipment not only for cancer diagnosis but also to inject the patch to the site of a tumor, when detected.

“This administration modality would enable, at least in early-stage cancer patients, the avoidance of open field surgery and colon resection,” Artzi says. “Local application of the triple therapy could thus improve patients’ quality of life and therapeutic outcome.”

Artzi is joined on the paper by João Conde, Nuria Oliva, and Yi Zhang, of IMES. Conde is also at Queen Mary University in London.

SOURCE

http://news.mit.edu/2016/patch-delivers-drug-gene-light-based-therapy-tumor-0725

Other related articles published in thie Open Access Online Scientific Journal include the following:

The Development of siRNA-Based Therapies for Cancer

Author: Ziv Raviv, PhD

https://pharmaceuticalintelligence.com/2013/05/09/the-development-of-sirna-based-therapies-for-cancer/

 

Targeted Liposome Based Delivery System to Present HLA Class I Antigens to Tumor Cells: Two papers

Reporter: Stephen J. Williams, Ph.D.

https://pharmaceuticalintelligence.com/2016/07/20/targeted-liposome-based-delivery-system-to-present-hla-class-i-antigens-to-tumor-cells-two-papers/

 

Blast Crisis in Myeloid Leukemia and the Activation of a microRNA-editing Enzyme called ADAR1

Curator: Larry H. Bernstein, MD, FCAP

https://pharmaceuticalintelligence.com/2016/06/10/blast-crisis-in-myeloid-leukemia-and-the-activation-of-a-microrna-editing-enzyme-called-adar1/

 

First challenge to make use of the new NCI Cloud Pilots – Somatic Mutation Challenge – RNA: Best algorithms for detecting all of the abnormal RNA molecules in a cancer cell

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2016/07/17/first-challenge-to-make-use-of-the-new-nci-cloud-pilots-somatic-mutation-challenge-rna-best-algorithms-for-detecting-all-of-the-abnormal-rna-molecules-in-a-cancer-cell/

 

miRNA Therapeutic Promise

Curator: Larry H. Bernstein, MD, FCAP

https://pharmaceuticalintelligence.com/2016/05/01/mirna-therapeutic-promise/

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BioPrinting Basics

Curator: Larry H. Bernstein, MD, FCAP

 

 

The ABCs of 3D Bioprinting of Living Tissues, Organs   5/06/2016 

(Credit: Ozbolat Lab/Penn State University)
(Credit: Ozbolat Lab/Penn State University)

Although first originated in 2003, the world of bioprinting is still very new and ambiguous. Nevertheless, as the need for organ donation continues to increase worldwide, and organ and tissue shortages prevail, a handful of scientists have started utilizing this cutting-edge science and technology for various areas of regenerative medicine to possibly fill that organ-shortage void.

Among these scientists is Ibrahim Tarik Ozbolat, an associate professor of Engineering Science and Mechanics Department and the Huck Institutes of the Life Sciences at Penn State University, who’s been studying bioprinting and tissue engineering for years.

While Ozbolat is not the first to originate 3D bioprinting research, he’s the first one at Penn State University to spearhead the studies at Ozbolat Lab, Leading Bioprinting Research.

“Tissue engineering is a big need. Regenerative medicine, biofabrication of tissues and organs that can replace the damage or diseases is important,” Ozbolat told R&D Magazine after his seminar presentation at Interphex last week in New York City, titled 3D Bioprinting of Living Tissues & Organs.”

3D bioprinting is the process of creating cell patterns in a confined space using 3D-printing technologies, where cell function and viability are preserved within the printed construct.

Recent progress has allowed 3D printing of biocompatible materials, cells and supporting components into complex 3D functional living tissues. The technology is being applied to regenerative medicine to address the need for tissues and organs suitable for transplantation. Compared with non-biological printing, 3D bioprinting involves additional complexities, such as the choice of materials, cell types, growth and differentiation factors, and technical challenges related to the sensitivities of living cells and the construction of tissues. Addressing these complexities requires the integration of technologies from the fields of engineering, biomaterials science, cell biology, physics and medicine, according to nature.com.

“If we’re able to make organs on demand, that will be highly beneficial to society,” said Ozbolat. “We have the capability to pattern cells, locate them and then make the same thing that exists in the body.”

3D bioprinting of tissues and organs

Sean V Murphy & Anthony Atala
Nature Biotechnology 32,773–785(2014)       doi:10.1038/nbt.2958

 

Additive manufacturing, otherwise known as three-dimensional (3D) printing, is driving major innovations in many areas, such as engineering, manufacturing, art, education and medicine. Recent advances have enabled 3D printing of biocompatible materials, cells and supporting components into complex 3D functional living tissues. 3D bioprinting is being applied to regenerative medicine to address the need for tissues and organs suitable for transplantation. Compared with non-biological printing, 3D bioprinting involves additional complexities, such as the choice of materials, cell types, growth and differentiation factors, and technical challenges related to the sensitivities of living cells and the construction of tissues. Addressing these complexities requires the integration of technologies from the fields of engineering, biomaterials science, cell biology, physics and medicine. 3D bioprinting has already been used for the generation and transplantation of several tissues, including multilayered skin, bone, vascular grafts, tracheal splints, heart tissue and cartilaginous structures. Other applications include developing high-throughput 3D-bioprinted tissue models for research, drug discovery and toxicology.

 

Future Technologies : Bioprinting
Bioprinting

3D printing is increasingly permitting the direct digital manufacture (DDM) of a wide variety of plastic and metal items. While this in itself may trigger a manufacturing revolution, far more startling is the recent development of bioprinters. These artificially construct living tissue by outputting layer-upon-layer of living cells. Currently all bioprinters are experimental. However, in the future, bioprinters could revolutionize medical practice as yet another element of the New Industrial Convergence.

Bioprinters may be constructed in various configurations. However, all bioprinters output cells from a bioprint head that moves left and right, back and forth, and up and down, in order to place the cells exactly where required. Over a period of several hours, this permits an organic object to be built up in a great many very thin layers.

In addition to outputting cells, most bioprinters also output a dissolvable gel to support and protect cells during printing. A possible design for a future bioprinter appears below and in the sidebar, here shown in the final stages of printing out a replacement human heart. Note that you can access larger bioprinter images on the Future Visions page. You may also like to watch my bioprinting video.

bioprinter

 

Bioprinting Pioneers

Several experimental bioprinters have already been built. For example, in 2002 Professor Makoto Nakamura realized that the droplets of ink in a standard inkjet printer are about the same size as human cells. He therefore decided to adapt the technology, and by 2008 had created a working bioprinter that can print out biotubing similar to a blood vessel. In time, Professor Nakamura hopes to be able to print entire replacement human organs ready for transplant. You can learn more about this groundbreaking work here or read this message from Professor Nakamura. The movie below shows in real-time the biofabrication of a section of biotubing using his modified inkjet technology.

 

Another bioprinting pioneer is Organovo. This company was set up by a research group lead by Professor Gabor Forgacs from the University of Missouri, and in March 2008 managed to bioprint functional blood vessels and cardiac tissue using cells obtained from a chicken. Their work relied on a prototype bioprinter with three print heads. The first two of these output cardiac and endothelial cells, while the third dispensed a collagen scaffold — now termed ‘bio-paper’ — to support the cells during printing.

Since 2008, Organovo has worked with a company called Invetech to create a commercial bioprinter called the NovoGen MMX. This is loaded with bioink spheroids that each contain an aggregate of tens of thousands of cells. To create its output, the NovoGen first lays down a single layer of a water-based bio-paper made from collagen, gelatin or other hydrogels. Bioink spheroids are then injected into this water-based material. As illustrated below, more layers are subsequently added to build up the final object. Amazingly, Nature then takes over and the bioink spheroids slowly fuse together. As this occurs, the biopaper dissolves away or is otherwise removed, thereby leaving a final bioprinted body part or tissue.

 

bioprinting stages

As Organovo have demonstrated, using their bioink printing process it is not necessary to print all of the details of an organ with a bioprinter, as once the relevant cells are placed in roughly the right place Nature completes the job. This point is powerfully illustrated by the fact that the cells contained in a bioink spheroid are capable of rearranging themselves after printing. For example, experimental blood vessels have been bioprinted using bioink spheroids comprised of an aggregate mix of endothelial, smooth muscle and fibroblast cells. Once placed in position by the bioprint head, and with no technological intervention, the endothelial cells migrate to the inside of the bioprinted blood vessel, the smooth muscle cells move to the middle, and the fibroblasts migrate to the outside.

In more complex bioprinted materials, intricate capillaries and other internal structures also naturally form after printing has taken place. The process may sound almost magical. However, as Professor Forgacs explains, it is no different to the cells in an embryo knowing how to configure into complicated organs. Nature has been evolving this amazing capability for millions of years. Once in the right places, appropriate cell types somehow just know what to do.

In December 2010, Organovo create the first blood vessels to be bioprinted using cells cultured from a single person. The company has also successfully implanted bioprinted nerve grafts into rats, and anticipates human trials of bioprinted tissues by 2015. However, it also expects that the first commercial application of its bioprinters will be to produce simple human tissue structures for toxicology tests. These will enable medical researchers to test drugs on bioprinted models of the liver and other organs, thereby reducing the need for animal tests.

In time, and once human trials are complete, Organovo hopes that its bioprinters will be used to produce blood vessel grafts for use in heart bypass surgery. The intention is then to develop a wider range of tissue-on-demand and organs-on-demand technologies. To this end, researchers are now working on tiny mechanical devices that can artificially exercise and hence strengthen bioprinted muscle tissue before it is implanted into a patient.

Organovo anticipates that its first artificial human organ will be a kidney. This is because, in functional terms, kidneys are one of the more straight-forward parts of the body. The first bioprinted kidney may in fact not even need to look just like its natural counterpart or duplicate all of its features. Rather, it will simply have to be capable of cleaning waste products from the blood. You can read more about the work of Organovoand Professor Forgac’s in this article from Nature.

Regenerative Scaffolds and Bones

A further research team with the long-term goal of producing human organs-on-demand has created the Envisiontec Bioplotter. Like Organovo’s NovoGen MMX, this outputs bio-ink ’tissue spheroids’ and supportive scaffold materials including fibrin and collagen hydrogels. But in addition, the Envisontech can also print a wider range of biomaterials. These include biodegradable polymers and ceramics that may be used to support and help form artificial organs, and which may even be used as bioprinting substitutes for bone.

Talking of bone, a team lead by Jeremy Mao at the Tissue Engineering and Regenerative Medicine Lab at Columbia University is working on the application of bioprinting in dental and bone repairs. Already, a bioprinted, mesh-like 3D scaffold in the shape of an incisor has been implanted into the jaw bone of a rat. This featured tiny, interconnecting microchannels that contained ‘stem cell-recruiting substances’. In just nine weeks after implantation, these triggered the growth of fresh periodontal ligaments and newly formed alveolar bone. In time, this research may enable people to be fitted with living, bioprinted teeth, or else scaffolds that will cause the body to grow new teeth all by itself. You can read more about this development in this article from The Engineer.

In another experient, Mao’s team implanted bioprinted scaffolds in the place of the hip bones of several rabbits. Again these were infused with growth factors. As reported inThe Lancet, over a four month period the rabbits all grew new and fully-functional joints around the mesh. Some even began to walk and otherwise place weight on their new joints only a few weeks after surgery. Sometime next decade, human patients may therefore be fitted with bioprinted scaffolds that will trigger the grown of replacement hip and other bones. In a similar development, a team from Washington State University have also recently reported on four years of work using 3D printers to create a bone-like material that may in the future be used to repair injuries to human bones.

In Situ Bioprinting

The aforementioned research progress will in time permit organs to be bioprinted in a lab from a culture of a patient’s own cells. Such developments could therefore spark a medical revolution. Nevertheless, others are already trying to go further by developing techniques that will enable cells to be printed directly onto or into the human body in situ. Sometime next decade, doctors may therefore be able to scan wounds and spray on layers of cells to very rapidly heal them.

Already a team of bioprinting researchers lead by Anthony Alata at the Wake Forrest School of Medicine have developed a skin printer. In initial experiments they have taken 3D scans of test injuries inflicted on some mice and have used the data to control a bioprint head that has sprayed skin cells, a coagulant and collagen onto the wounds. The results are also very promising, with the wounds healing in just two or three weeks compared to about five or six weeks in a control group. Funding for the skin-printing project is coming in part from the US military who are keen to develop in situ bioprinting to help heal wounds on the battlefield. At present the work is still in a pre-clinical phase with Alata progressing his research usig pigs. However, trials of with human burn victims could be a little as five years away.

The potential to use bioprinters to repair our bodies in situ is pretty mind blowing. In perhaps no more than a few decades it may be possible for robotic surgical arms tipped with bioprint heads to enter the body, repair damage at the cellular level, and then also repair their point of entry on their way out. Patients would still need to rest and recuperate for a few days as bioprinted materials fully fused into mature living tissue. However, most patients could potentially recover from very major surgery in less than a week.

Cosmetic Applications …

Bioprinting Implications …

More information on bioprinting can be found in my books 3D Printing: Second Editionand The Next Big Thing. There is also a bioprinting section in my 3D Printing Directory. Oh, and there is also a great infographic about bioprinting here. Enjoy!

 

How to print out a blood vessel

New work moves closer to the age of organs on demand.

Blood vessels can now be ‘printed out’ by machine. Could bigger structures be in the future?SUSUMU NISHINAGA / SCIENCE PHOTO LIBRARY

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