As I hope you know, HIV infection rates are growing among women as heterosexual transmission becomes more common, and there are places in the world where up to 74% of the new cases each year are in females. Biology is part of the problem. The skin lining the vaginal tract contains immune-system cells that fight infection and are the same cells that HIV infects. Social customs that allow older men to have multiple sexual partners and take younger partners are also a problem, as is the fact that most countries do pretty poor sexuality education.
This places a huge burden on women to prevent infection, especially since the best prevention, male condoms, require male cooperation. One proposed answer is vaginal microbicides that are virus-killing gels and creams that a woman can use without male permission, but they have to be inserted 1-2 hours before sex, and they "leak" out. There are at least five products in testing now.
However, in December there were several news articles about a proposed better way for women to protect themselves from HIV. One was in the Economist, that described a squishy microbicide-containing lining for the vagina from Patirck Kiser and colleagues at the University of Utah.
Talk about magic - this "molecular condom" starts off as a liquid that a woman can insert into her vagina, where her body temperature and the acidity of her vagina turn the liquid into a gel. The gel stays in her vagina until the alkalinity of semen turns the gel back into a liquid, releasing antimicrobial drugs that kill HIV. How cool would that be?