Nanofibers can physically block sperm, as shown here. The fibers can also release spermicide and other chemicals. In theory, it shouldn't be too difficult to protect oneself against HIV and other STIs, as well as pregnancy. Condoms, after all, are very effective. But in practice, it's not so simple. Many of the people at high risk for HIV, for instance, are women who don't have much control over whether their partners wear protection. Taking daily medication or applying drug-laden gels also have their downsides---people forget, they find it inconvenient, there's social stigma. So finding ways to provide protection thats get over these hurdles is an important research goal. Scientists at the University of Washington think a new delivery platform may be a step in the right direction. They've created nanofibers embedded with pre-existing drugs against HIV-1, HIV-2, and sperm. Theoretically, these stretchy microfabrics could be inserted into the vagina directly or on the surface of another device, such as a vaginal ring, and act as both a physical and chemical barrier. The real kicker is the fact that the nanofiber can release the drugs slowly, so the device could protect women against STIs for an extended period of time after insertion. To form these fibers, the scientists use a method called electrospinning. They apply voltage to a mix of liquid polymers and antiretroviral drugs. As the gooey concoction whips through the air, it forms fibers that stretch to diameters as thin as one 25-millionth of an inch. The scientists then collect the flying fibers on a plate to form the drugged fabrics. The size and solubility of the fibers can be carefully controlled---one type of fiber was designed to dissolve within minutes for immediate protection, while another took days to dissolve. While the drugs themselves are nothing new, this versatility gives the nanofibers the potential to be a more discreet and convenient delivery option than existing gels or pills. So far, the fibers have proven effective in the lab but have yet to be tested beyond the petri dish---where it really counts.