According to data unveiled at the 2008 Microbicide Conference in New Delhi today, the future finally looks bright for rectal microbicide gels as an effective way of preventing transmission of HIV and other sexually transmitted diseases, Aidsmap reports (Aidsmap.com, 2/25).

Preliminary data from the “U19” rectal microbicide program showed that the gel—which contains the non-nucleoside HIV drug UC-781—showed little signs of toxicity in human volunteers. According to Aidsmap, the U19 program also utilized an “in vivo–ex vivo” HIV infection model to monitor the efficacy of the gel in HIV prevention through application in cellular explants—small pieces of tissue kept alive in a nutrient medium—which were infected with two doses of the virus. The second dose contained 100 times more virus than the first.

After three weeks, explants grown from biopsies taken after gel application were shown to resist infection when exposed to the higher dose of HIV, suggesting that UC-781 may one day be utilized as a viable anal sex HIV prevention tool.