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Posts Tagged ‘human papillomavirus hpv’

Non-toxic antiviral nanoparticles with a broad spectrum of virus inhibition

Curator and Reporter: Dr. Premalata Pati, Ph.D., Postdoc

Infectious diseases account for 20% of global deaths, with viruses accounting for over a third of these deaths (1). Lower respiratory effects and human immunodeficiency viruses (HIV) are among the top ten causes of death worldwide, both of which contribute significantly to health-care costs (2). Every year, new viruses (such as Ebola) increase the mortality toll. Vaccinations are the most effective method of avoiding viral infections, but there are only a few of them, and they are not available in all parts of the world (3). After infection, antiviral medications are the only option; unfortunately, only a limited number of antiviral medications are approved in this condition. Antiviral drugs on a big scale that can influence a wide spectrum of existing and emerging viruses are critical.

The three types of treatments currently available are small molecules (such as nucleoside analogues and peptidomimetics), proteins that stimulate the immune system (such as interferon), and oligonucleotides (for example, fomivirsen). The primary priorities include HIV, hepatitis B and C viruses, Herpes Simplex Virus (HSV), human cytomegalovirus (HCMV), and influenza virus. They work mainly on viral enzymes, which are necessary for viral replication but which differ from other host enzymes to ensure selective function. The specificity of antivirals is far from perfect because viruses rely on the biosynthesis machinery for reproduction of infected cells, which results in a widespread and inherent toxicity associated with such therapy. However, most viruses mutate rapidly due to their improper replicating mechanisms and so often develop resistance (4). Finally, since antiviral substances are targeted at viral proteins, it is challenging to build broad-based antivirals that can act with a wide range of phylogenetic and structurally different virus.

Over the last decade breakthroughs in nanotechnology have led to scientists developing incredibly specialized nanoparticles capable of traveling in specific cells through a human body. A broad spectrum of destructive viruses is being targeted and not only bind to, but also destroy, by modern computer modeling technology.

An international team of researchers led by the University of Illinois at Chicago chemistry professor Petr Kral developed novel anti-viral nanoparticles that bind to a variety of viruses, including herpes simplex virus, human papillomavirus, respiratory syncytial virus, Dengue, and lentiviruses. In contrast to conventional broad-spectrum antivirals, which just prevent viruses from invading cells, the new nanoparticles eradicate viruses. The team’s findings have been published in the journal “Nature Materials.”

A molecular dynamics model showing a nanoparticle binding to the outer envelope of the human papillomavirus. (Credit: Petr Kral) https://today.uic.edu/files/2017/09/viralbindingcropped.png

The goal of this new study was to create a new anti-viral nanoparticle that could exploit the HSPG binding process to not only tightly attach with virus particles but also to destroy them. The work was done by a group of researchers ranging from biochemists to computer modeling experts until the team came up with a successful nanoparticle design that could, in principle, accurately target and kill individual virus particles.

The first step to combat many viruses consists in the attachment of heparin sulfate proteoglycan on cell surfaces to a protein (HSPG). Some of the antiviral medications already in place prevent an infection by imitating HSPG’s connection to the virus. An important constraint of these antivirals is that not only is this antiviral interaction weak, it does not kill the virus.

Kral said

We knew how the nanoparticles should bind on the overall composition of HSPG binding viral domains and the structures of the nanoparticles, but we did not realize why the various nanoparticles act so differently in terms of their both bond strength and viral entry in cells

Kral and colleagues assisted in resolving these challenges and guiding the experimentalists in fine-tuning the nanoparticle design so that it performed better.

The researchers have employed advanced computer modeling techniques to build exact structures of several target viruses and nanoparticles up to the atom’s position. A profound grasp of the interactions between individual atom groupings in viruses and nanoparticles allows the scientists to evaluate the strength and duration of prospective links between these two entities and to forecast how the bond could change over time and eventually kill the virus.


Atomistic MD simulations of an L1 pentamer of HPV capsid protein with the small NP (2.4 nm core, 100 MUP ligands). The NP and the protein are shown by van der Waals (vdW) and ribbon representations respectively. In the protein, the HSPG binding amino acids are displayed by vdW representation.

Kral added

We were capable of providing the design team with the data needed to construct a prototype of an antiviral of high efficiency and security, which may be utilized to save lives

The team has conducted several in vitro experiments following the development of a prototype nanoparticle design which have demonstrated success in binding and eventually destroying a wide spectrum of viruses, including herpes simplex, human papillomaviruses, respiratory syncytial viruses and dengue and lentiviruses.

The research is still in its early phases, and further in vivo animal testing is needed to confirm the nanoparticles’ safety, but this is a promising new road toward efficient antiviral therapies that could save millions of people from devastating virus infections each year.

The National Centers of Competence in Research on Bio-Inspired Materials, the University of Turin, the Ministry of Education, Youth and Sports of the Czech Republic, the Leenards Foundation, National Science Foundation award DMR-1506886, and funding from the University of Texas at El Paso all contributed to this study.

Main Source

Cagno, V., Andreozzi, P., D’Alicarnasso, M., Silva, P. J., Mueller, M., Galloux, M., … & Stellacci, F. (2018). Broad-spectrum non-toxic antiviral nanoparticles with a virucidal inhibition mechanism. Nature materials17(2), 195-203. https://www.nature.com/articles/nmat5053

Other Related Articles published in this Open Access Online Scientific Journal include the following:

Rare earth-doped nanoparticles applications in biological imaging and tumor treatment

Reporter: Irina Robu, PhD

https://pharmaceuticalintelligence.com/2020/10/04/rare-earth-doped-nanoparticles-applications-in-biological-imaging-and-tumor-treatment/

Nanoparticles Could Boost Effectiveness of Allergy Shots

Reporter: Irina Robu, PhD

https://pharmaceuticalintelligence.com/2019/05/25/nanoparticles-could-boost-effectiveness-of-allergy-shots/

Immunoreactivity of Nanoparticles

Author: Tilda Barliya PhD

https://pharmaceuticalintelligence.com/2012/10/27/immunoreactivity-of-nanoparticles/

Nanotechnology and HIV/AIDS Treatment

Author: Tilda Barliya, PhD

https://pharmaceuticalintelligence.com/2012/12/25/nanotechnology-and-hivaids-treatment/

Nanosensors for Protein Recognition, and gene-proteome interaction

Curator: Larry H Bernstein, MD, FCAP

https://pharmaceuticalintelligence.com/2016/01/30/nanosensors-for-protein-recognition-and-gene-proteome-interaction/

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Reported by: Dr. Venkat S Karra, Ph.D.

Two-thirds of Americans aged 15 to 24 have engaged in oral sex, according to a broad new survey of young people’s sexual habits.

The data, published Aug. 16 in the U.S. Centers for Disease Control and Prevention’s National Health Statistics Reports, also reveals that about one-quarter of young people try oral sex before they engage in intercourse.

“I don’t think these numbers are surprising, but I do think that it’s important that this data has been captured at all, because it’s really important to have, and has for a long time been a fuzzy area in our understanding of sexual behavior,” said one expert, Dr. Christopher Hurt, A clinical assistant professor in the division of infectious disease at the University of North Carolina.

He said the findings are also valuable because too many people of all ages mistakenly believe that oral sex is “risk-free.”

“That’s not the case,” Hurt said. “Studies looking, for example, at patients visiting STD [sexually transmitted disease] clinics have shown that 5 to 10 percent have gonorrhea in the throat. And it’s often asymptomatic and can be transmitted through oral sex.”

Gonorrhea is becoming increasingly resistant to antibiotics, and a report released last week by the CDC noted that certain strains are resistant to all but one such drug. Oral sex can also raise risks for infection with chlamydia, herpes and syphilis, the CDC noted.

Oral sex is also increasingly linked to transmission of the human papillomavirus (HPV), which may be linked to cancers of the throat and oral cavity, in addition to cervical cancer, experts say.

While the odds of contracting any sexually transmitted disease from oral sex remain lower than that for unprotected intercourse, the CDC has stated that “numerous studies have demonstrated that oral sex can result in the transmission of HIV and other sexually transmitted diseases.”

The new report is based on data from the agency’s seventh National Survey of Family Growth, involving interviews conducted between 2007 and 2010 with nearly 22,700 people between the ages of 15 and 44.

Even though the survey found that about one-quarter of Americans aged 15 to 24 engaged in oral sex before they moved on to intercourse, for about another quarter of respondents the opposite was true — they tried penile-vaginal intercourse prior to engaging in oral sex. Among males, 12 percent said their first experience with both practices occurred at the same time, while a little more than 7 percent of women said that that was the case for them.

Examining behaviors solely among the youngest participants — those 15 to 19 years old — the CDC team found that more than half of American girls and boys in this age group had already engaged in some form of sexual contact with someone of the opposite sex (55 percent of girls and 58 percent of boys).

Among the survey’s other findings:

  • About 5 percent of women and nearly 7 percent of men aged 15 to 24 said that at the time of the survey they had only engaged in oral sex, not intercourse. Another 28 percent of women and nearly 29 percent of men said they had had no sexual experiences with an opposite-sex partner whatsoever.
  • Among girls aged 15 to 19 years, oral sex and vaginal intercourse experience were equally common (48 percent and 47 percent, respectively), while among similarly aged boys oral sex was slightly more common (49 percent) compared to intercourse (44 percent).
  • Rates of sexual behaviors did not appear to vary widely by race. For example, among females aged 15 to 24, nearly three-quarters (74 percent) of black women, 68 percent of Hispanic women and 66 percent of white women said they had had vaginal intercourse.
  • Among males aged 15 to 24, about seven in 10 black and Hispanic men said they had had intercourse, compared with 63 percent of white men. There were no appreciable racial differences observed in terms of the percentages of those who said they had engaged in oral sex, the CDC survey found.

According to Hurt, young people need to be properly armed with knowledge before they engage in their first sexual activity, and that includes information on the risks that accompany oral sex.

“I would say that the risk of STD transmission through oral sex is underappreciated and underestimated,” he said. “As part of sex education programs, kids need to be made aware of that fact: that oral sex is not a completely risk-free activity.”

SOURCES: Christopher Hurt, M.D., clinical assistant professor, division of infectious diseases, University of North Carolina, Chapel Hill; Aug. 16, 2012, U.S. Centers for Disease Control and Prevention’s National Center for Health Statistics report, Prevalence and Timing of Oral Sex with Opposite-Sex Partners Among Females and Males Aged 15-24 Years: United States: 2007-2010

Source

http://www.nlm.nih.gov/medlineplus/news/fullstory_128320.html

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