Thermoreversible Gel as a Candidate Barrier to Prevent the Transmission of HIV-1 and Herpes Simplex Virus Type 2

Background: Sexually transmitted diseases (STDs) caused by HIV, herpes simplex virus (HSV), and other pathogens are spreading dramatically. The need to develop active products and vehicles to reduce this epidemic is urgent. Goal: The efficacy of a thermoreversible gel formulation as a possible barrier to prevent the transmission of pathogens causing STDs was evaluated. Study Design: This evaluation investigated the ability of the gel formulation to prevent infection of susceptible cells by HIV-1 and HSV-2 in vitro, the diffusion of radiolabeled herpes virus and micelles of polymer through an insertion membrane, and the electron microscopic appearance of herpes virus and gel alone or mixed together. Results: The gel formulation prevents infection of susceptible cells by HIV-1 and HSV-2. It acts as an effective artificial physical barrier against the herpes virus within the first 4 hours of incubation. Herpes virus is coated by the gel or entrapped within micelles of the gel, which could hinder its attachment to target cells and inhibit its infectivity. Conclusion: This thermoreversible gel formulation represents an attractive matrix for the incorporation of microbicides to prevent the spread of STDs.