Styrene Maleic Anhydride formulated polyelectrolyte hydrogel with selective antimicrobial property, potentially favorable for the application as female contraceptive implant

Abstract

Event Abstract Back to Event Styrene Maleic Anhydride formulated polyelectrolyte hydrogel with selective antimicrobial property, potentially favorable for the application as female contraceptive implant Bhuvaneshwaran Subramanian1, 2, Arun Prabhu Rameshbabu1, Kuntal Gosh3, M Selvakumar4, Piyali Basak2, Santanu Dhara1 and Sujoy K Guha1 1 Indian Institute of Technology Kharagpur, School of Medical Science and Technology, India 2 Jadavpur University, School of Bio-Science and Engineering, India 3 Vidyasagar University, Department of Microbiology, India 4 Indian Institute of Technology Kharagpur, Rubber Technology Centre, India Introduction: Polymeric implants like Intra Uterine Contraceptive Devices (IUD) is one among the most popular female contraceptive method. IUD associated Reproductive Tract Infections (RTI) are prominent worldwide issue associated with IUD using women[1]. Healthy human reproductive tract is colonized by variety of bacterial species with lactobacilli as a predominant and beneficial group of microorganisms. Opportunistic pathogens like Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, etc are associated in the pathogenesis of IUD associated reproductive tract infection[2]. Herein we evaluated the antimicrobial activity of styrene maleic anhydride copolymer hydrogel formulation against opportunistic pathogens like E. Coli, S. aureus, P. auregenosa as well as specifying its safety towards healthy human lactobacillus[3]. Spreadability and rheological characterization of the hydrogel formulation with Simulated Uterine Fluid (SUF) was analyzed. Gelation kinetics, shear rate dependent viscosity were measured for studying retention potency of the hydrogel post implantation[4]. Toxicity evaluation on uterine primary cell lines revealed no significant toxicity observed by the polyelectrolyte polymeric hydrogel. Materials and Methods: Bacterial colonies isolated from frozen stock were restreaked on their corresponding agar plates. All the test organisms were exposed to hydrogel. Zone of incubation was measured using Vernier calipers after incubation. Direct contact inhibition studies were performed using time kill method with little modifications. Each test bacteria included a growth control without a test sample as negative control. At 0-, 1-, 6-, 9- and 24- hour time intervals, 300µL of the test bacteria culture was removed for viable cell enumeration by drop plate counting method. In order to observe the rate of gelation in accordance with time, the gelation forming ability was studied through complex modulus (G*) and complex viscosity (η*) against time sweep measurement in the linear viscoelastic range (at frequency 1 Hz and shear stress of 10 Pa) before and after addition of SUF (pH 7.6) at 37oC. Test samples its dilutions showed shear thinning behavior due to the gradual reduction of viscosity by increasing the shear rate. The shear rate dependent viscosity of hydrogel and its dilutions show shear thinning behavior. Toxicity of hydrogel test samples were analysed on endometrial primary cell lines for 6, 24 and 48 hours. Results and Discussion: Agar well diffusion and indirect assay of polymeric hydrogel at 3% inhibited the growth of E.coli, S.aureus, P.auregenosa and that the tested Lactobacillus species can tolerate. Addition of SUF in polymeric hydrogel resulted in instantaneous gel formation in which is evidenced by the rapid rise in G* and η* demonstrating the viscoelastic nature of the gel. Test samples its dilutions showed significant spreadability and shear thinning behavior due to the gradual reduction of viscosity by increasing the shear rate. The shear rate dependent viscosity of hydrogel and its dilutions show shear thinning behavior . Indirect hydrogel exposure assay showed no significant toxicity in the endometrial cell lines at different time intervals. Conclusion: These in vitro characterization results have inference for the efficiency of polyelectrolyte hydrogel to retain in upper reproductive tract for extended duration after implantation without producing any significant level of toxicity. Ministry of Health and Family Welfare, Government of India