University of Utah researchers have developed a vaginal “molecular condom” that starts as a fluid substance to be inserted by a woman vaginally, that becomes a gel at body temperature and at the vaginal fluid pH of 4.2, and then in the presence of sperm with a pH of 7.7, it become a liquid again, only to release an antiviral drug load to block infection by the HIV.
“We have developed a new vaginal gel that we call a molecular condom because it is composed of molecules that are liquid at room temperature and, when applied in the vagina, will spread and turn into a gel and effectively coat the tissue,” says Patrick Kiser, an assistant professor of bioengineering. “It’s a smart molecular condom because we designed this gel to release anti-HIV drugs when the gel comes into contact with semen during intercourse.”
“The ultimate hope for this technology is to protect women and their unborn or nursing children from the AIDS virus,” but the molecular condom is five years away from tests in humans and roughly 10 years until it might be in widespread use, Kiser says.
Kiser and colleagues report development of the molecular condom in a study to be published online Monday, Dec. 11, 2006, in the Journal of Pharmaceutical Sciences.
The molecular condom is part of a worldwide research effort to develop “microbicides” — drug-delivery systems such as gels, rings, sponges or creams to prevent infection by the human immunodeficiency virus and other sexually transmitted diseases. HIV causes AIDS, which cripples the immune system, leaving patients vulnerable to other infections, cancers and death…
The molecular condom is a polymer — a molecule with a repeating, chain-like structure — made from three chemicals in these proportions:
80 parts of N-isopropylacrylamide. 15 parts of butyl methacrylate, which is used in coatings, adhesives, solvents, resins, oil additives and to finish leather and paper. Five parts acrylic acid, which is used in lubricant and spermicidal gels.
“The three together have the property of liquid at room temperature and vaginal pH, solid at body temperature and vaginal pH, and liquid at body temperature and semen pH,” Kiser says.