Wonder condom in the making!

Scientists have developed a gel like substance, promising to be an effective replacement for latex condoms.

According to them, the gel becomes semi-solid in response to pH changes caused by the introduction of semen, thereby forming a nanoscopic mesh of crosslinked molecules so tightly woven that they form a serious barrier to the virus.

For years, researchers have been working on microbicides (intravaginal gels, rings, and films) that can prevent the transmission of viruses such as the human immunodeficiency virus (HIV). Only a handful ever made it to human clinical trial, and ran into issues such as women not using them, or the antiviral drugs in the microbicides not lasting long enough. Some microbicides even seemed to increase the risk of transmission.

Now, researchers at the University of Utah seem to have greatly improved on a microbicide they first wrote about in 2006, according to a study published this week in the journal Advanced Functional Materials.

The new gel becomes more solid and impenetrable as changes in pH alter the strength of the bond between the gel's two key components, both of which are polymers, or long, chain-like molecules made of many smaller, repeating units: PBA, or phenylboronic acid, and SHA, or salicylhydroxamic acid.

According to the University of Utah press release, the mesh of molecules--at 30 to 50 nanometers wide--should be able to block any HIV particle, which is two to three times thicker (roughly 100 nanometers wide). This should also block sperm, which measure 5,000 to 10,000 nanometers (5 to 10 microns). One way to think about this nano scale is that a strand of human hair is generally about 100,000 nanometers wide (100 microns), making it 10 to 20 times thicker than sperm and 2,000 to 3,333 times thicker than an HIV particle.