A pH responsive multifunctional sericin-pyrrole hydrogel with inherent antibacterial and antioxidant activities

Abstract

Hydrogels derived from natural materials with intrinsic bioactivities and pH responsiveness have attracted considerable interest in biomedical applications due to their versatile functionality. In this study, a robust multifunctional sericin-pyrrole hydrogel (S8P2) was synthesized using sericin isolated from fibroin-deficient silkworm cocoons and cross-linked with pyrrole. The resulting hydrogel exhibits fast gelation, a uniform microporous structure (15 μm pore size, 65% porosity), high transparency (~65% transmittance), pH-responsive swelling and degradation behavior, and excellent mechanical properties including prominent elastic recovery and a compressive modulus of 50 kPa. Notably, the hydrogel demonstrates broad-spectrum antibacterial efficacy against both S. aureus and P. aeruginosa, along with significantly improved antioxidant activity compared to sericin alone. Furthermore, it shows excellent cytocompatibility with L929 fibroblasts, high cell adhesion, and minimal hemolysis (<5%). These attributes position the S8P2 hydrogel as a highly promising material for applications in wound dressing, tissue engineering scaffolds, and controlled drug delivery systems.