It may be possible to create a dissolvable cloth that releases HIV-prevention and pregnancy-prevention drugs. It's hard to believe, but the condom is still the only way to protect against pregnancy and HIV at the same time.
But researchers say they believe they can develop a kind of 21st-century contraceptive that offers superior protection against pregnancy and sexually transmitted diseases and that people will like enough to use consistently. A paper describing early work on the project was published earlier this month in the journal PLoS One.
The research team, led by Kim Woodrow at the University of Washington, received a grant of nearly $1 million last month from the Bill & Melinda Gates Foundation to pursue the research. The product is an electrically spun cloth with nanometer-sized fibers that can dissolve to release drugs, such as medications that prevent pregnancy and HIV infection. The drug-eluting fibers represent "multipurpose prevention technology," a method that simultaneously prevents sexually transmitted infections and unintended pregnancy through a combined physical and chemical barrier.
"Condoms and vaginal rings and IUDs have been around for a very long time," Cameron Ball, a co-author of the paper and graduate student in bioengineering, told TakePart. "People would like more options. No one option will be the silver bullet. The idea is to have multiple options that people can choose for their lifestyle." Improved methods to protect against STDs and pregnancy are needed in both developing and developed countries.
The spermacide nonoxynol-9 is highly effective at pregnancy prevention but promotes vaginal inflammation, which then increases the risk of STD transmission. "What we're hoping to provide is a method of drug delivery that could be used with a variety of drug compounds," Ball says. "There are multiple products in the development pipeline to address this need. These are largely vaginal rings, but vaginal rings are limited in what they are able to deliver.
They deliver compounds that are less water soluble. Using fibers allows you to work with multiple drugs with different properties. You can have combinations of pharmaceutical agents that you couldn't necessarily have with a vaginal ring or with a condom." During electrospinning, an electric field is used to launch a charged fluid jet through the air to create extremely delicate nanometer-scale fibers that stick to a collection plate.
(One nanometer is about one 25-millionth of an inch.) The stretchy fibers are the platform for delivering medications in the same way that drugs are delivered through pills or gels. The fibers can also carry larger molecules, such as proteins and antibodies, that are hard to deliver through other methods. So far, the team has created a fabric that serves as a physical barrier to block sperm or to release drugs, such as contraceptives and antiviral medications.
The fabric dissolves within minutes, which is considered a benefit because it offers immediate and discreet protection. But the approach also allows for controlled release of multiple compounds, Ball says. Last year, a study aimed at preventing heterosexual HIV transmission using a gel with the drug tenofovir failed—the likely result of the drug's strength fading by the time of sex. "If you can have a longer-lasting gel with nanoparticles, that would be beneficial," Ball says.
"We're trying to fill a niche in terms of product lifespan." The cloth could be inserted directly into the body or used as a coating on vaginal rings or other products, Ball says. While the primary goal of the research is for products that can be used in places like Africa, where HIV transmission is especially high, the technology could appeal to a wide range of societies and cultures.
"You could have fibers that stay in place for longer or be shaped in the shape of a diaphragm," he says. "You could include herpes medication. Herpes prevention is somewhat controversial—it's not clear whether taking herpes medications prophylactically will help prevent the spread of the virus. That is another application, potentially."