Impact of styrene maleic anhydride (SMA) based hydrogel on rat fallopian tube as contraceptive implant with selective antimicrobial property

Abstract

Development of non-hormonal female contraception is a need to combat against increasing population growth. The presently available short term or long term female contraceptives and sterilization methods have their own restrictions and side effects. With this objective, herein, we describe an innovative insight about the use of hydrogel formulation consisting of Styrene Maleic Anhydride (SMA) dissolved in Dimethyl Sulfoxide (DMSO) as non-hormonal fallopian tube contraceptive implant. Firstly, in vitro behavior of SMA hydrogel was evaluated by in vitro swelling and rheological properties to comprehend the polymeric hydrogel property post implantation inside the fallopian tube. Simulated Uterine Fluid (SUF) was used to simulate female reproductive tract environment in this study. Mechanical strength of the hydrogel when subjected to dynamic environment post implantation in the fallopian tube was estimated by the G′ values demonstrated. SMA hydrogel expressed selective antimicrobial activity against opportunistic pathogens (Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus) while having limited consequence over the growth of Lactobacillus spp. After confirmation of cytocompatibility against primary rat endometrial cell lines, the polymeric hydrogel was implanted inside the uterine horns of Sprague-Dawley rats. In vivo biocompatibility of the hydrogel was confirmed by histological and immunohistochemical evaluation of uterine tissue sections. Hematology, blood biochemistry and organ toxicity (kidney, liver, spleen, lungs and heart) also revealed biocompatibility of SMA hydrogel. The results of the current study indicated that the SMA copolymer dissolved in DMSO to form hydrogel has excellent biocompatibility for application as female contraceptive gel which can be implanted in the fallopian tube.