Poly(sodium 4-styrene sulfonate): evaluation of a topical microbicide gel against herpes simplex virus type 2 and Chlamydia trachomatis infections in mice.

Objective: To investigate the in vivo activity of poly(sodium 4-styrene sulfonate) (T-PSS) gel formulations as topical microbicides.

Methods: The ability of the gel formulations to reduce the incidence of infection when applied prior to pathogen challenge was examined in mouse models of vaginal herpes simplex type 2 (HSV-2) and Chlamydia trachomatis infection, and rectal HSV-2 infection.

Results: In the vaginal HSV-2 challenge studies, 10% T-PSS gel provided significant protection against infection, even when administered 60 min prior to virus challenge (P < 0.0001). Both 5% and 10% T-PSS gel formulations significantly reduced the incidence of upper genital tract C. trachomatis infection in animals treated up to 5 min before challenge (P < 0.001). However, no protection against C. trachomatis infection was seen in animals treated 30 min before challenge. In mice challenged rectally with HSV-2, both the 5% and 10% T-PSS gels significantly reduced infection at 20 s (P < 0.01 for both). However, only the 10% gel provided significant protection when administered 5 min before challenge (P < 0.01).

Conclusions: T-PSS gel formulations have promising in vivo activity as topical microbicides.