Biocompatible and antibacterial gelatin-based polypyrrole cryogels

Abstract

Polypyrrole-gelatin cryogels were synthesized by oxidative cryopolymerization of pyrrole in the presence of gelatin. Vibrational spectroscopy confirmed formation of doped polypyrrole. Mechanical and pore structure stability of the resulting macroporous materials (pore size 10–50 μm) was shown to increase with increasing of gelatin content in initial polymerization medium, reaching plateau at 6 wt%. Thermal stability of polypyrrole-gelatin cryogels was found to be enhanced in comparison to its individual components. Electrical conductivity of all prepared cryogels (2–5 S cm−1) was similar to that of conventional polypyrrole. Cytotoxicity of polypyrrole-gelatin cryogels was found to decrease with increasing of gelatin concentration in the initial reaction mixture. The cryogel obtained using 8 wt% of gelatin showed the lowest cytotoxic effect reaching only mild cytotoxicity at 100% extract concentration. Polypyrrole-gelatin gels showed significant level of antibacterial activity without additional antibacterial agents. © 2020 Elsevier Ltd