New Vaginal Cream Blocks HIV Transmission

After years of work on a microbicide, researchers in Texas and Mexico have come up with one using silver nanoparticles that works in a completely different way.

It's a long way from market, but researchers from the University of Texas, in collaboration with Humberto Lara Villegas, specialist in nanoparticles and virology from the University of Monterrey, Mexico, have created a new vaginal cream that prevents HIV transmission. The cream uses silver nanoparticles to block the virus from entering CD4 immune cells.

Lara Villegas, one of the University of Monterrey researchers, told Science Daily that HIV normally enters CD4 cells "with the aid of a protein known as GP120, which allows the virus adherence to the cells. This same principle is used by silver nanoparticles to attach themselves to this protein and block it, turning the virus inactive."

SD reports that the vaginal cream "has been tested in samples of human tissue and has proven the efficiency of silver nanoparticles to avoid the transmission of the virus through cervical mucous membrane." Villegas also told the publication that the cream take less than a minute to begin working and can last up to 72 hours, and because of the unusual blocking process, would provide protection for the woman and her partner, regardless of who might be carrying HIV.

"Right now, I am certain that this microbicide is going to avoid the virus entering the organism, but I cannot yet assure that is totally harmless, because the clinical trials are a long and expensive process," Villegas said.

The cream will now go into testing on mice that accept human cells and later to live human clinical trials, meaning the vaginal cream won't be available at your local drugstore any time soon.

 But when it is, Villegas says, it might do more than block HIV; it could be used to prevent transmission of other sexually trasmitted infections like HPV and chlamydia.