Traditionally, women's options for lowering their risk of contracting HIV have been relatively limited: Use condoms or don't have sex. Don't inject drugs. And get tested.
But if a team of bioengineers with the University of Washington succeeds at ushering its new research through clinical trials, women may soon be able to turn to dissolvable "tampons" that deliver HIV-preventing medication minutes before having sex.
In a preliminary study published in the journal Antimicrobial Agents and Chemotherapy, the researchers combined silky, electrically spun fibers with maraviroc -- a drug currently approved to help treat HIV infections that may also prevent healthy people from acquiring the virus. Within minutes of coming into contact with moisture, the fibers dissolve, releasing a high dose of the medication.
The hope is that women will be able to discretely insert a tampon-like device containing the fibers into their vaginas -- either with their fingers or an applicator -- minutes before sex.
"We envision a product that could dissolve, pretty much instantaneously, into a gel and then spread around the vagina during sex," Cameron Ball, lead author on the paper and a doctoral student in bioengineering with the University of Washington, told The Huffington Post.
"We want something that dissolves quickly so that people can say, 'Hey, I wasn't planning on it, but I'm going to have sex in five minutes so I need to use this product, and I want it to be completely dissolved before that,'" he added. (The new "tampons" are not intended to be used for feminine hygiene purposes.)
For years, HIV prevention efforts have explored the role of Pre-Exposure Prophylaxis, or PrEP, which refers to medications used to prevent HIV infection in high-risk individuals. That category includes men or women in relationships with HIV-positive partners, anyone who injects drugs and individuals who regularly have unprotected sex with partners whose HIV status they do not know and who may be high-risk themselves. The drugs are delivered via a pill, taken daily.
But researchers have also investigated how topically applied microbicides -- gels, creams or films inserted into the vagina or rectum immediately before sex -- can help prevent HIV infection. Those delivery systems, however, are not without flaws.
"Follow-up trials have shown that the real barrier for women in using them is that they don't adhere to the products -- there's leakage that makes it messy for them to use, so we're interested in creating a different form of the drug," Ball said. "Basically, a different product that women might be more likely to use."
The new fibers could also potentially be used for the prevention of other sexually transmitted infections such as herpes, Ball said, or as a form of contraception.
But it will be years before women are able to buy these products, he cautioned.
"It would probably take five years to get into a clinical study phase, with humans, and then depending on how that goes, it would probably take up to another five years before these types of things might be seen on the shelf of a local Walgreens or CVS," he said.
Globally, women make up half of all people living with HIV, and they are twice as likely to contract HIV from men during intercourse as vice versa. In the United States, women account for 20 percent of new infections and, in 2009, made up 24 percent of those living with HIV, according to the Centers for Disease Control and Prevention.