A Sericin-Reinforced Poly(vinyl alcohol) Composite Hydrogel Integrating Sericin-Associated Silver Nanoparticles and Dual Growth Factors for Diabetic Wound Repair

Abstract

Abstract Diabetic wound repair requires polymeric dressings that combine structural stability, swelling behavior, antibacterial activity, and biological support within a single material platform. Here, we report a sericin-reinforced poly(vinyl alcohol) (PVA) composite hydrogel incorporating silver nanoparticles formed in a sericin-containing matrix (Sericin-AgNPs) and the complementary growth factors hepatocyte growth factor (HGF) and keratinocyte growth factor-2 (KGF-2). The hydrogel was prepared through a freeze–thaw cross-linking strategy that generated a porous, elastic, and conformable polymer network while using sericin as a biocompatible matrix component that participates in the in situ formation of AgNPs. The selected SAP5 formulation exhibited a porosity of 62.02%, an equilibrium swelling ratio of 59.13%, and more than 70% mass retention after 28 days. In vitro assays showed that the Sericin-AgNPs provided broad-spectrum antibacterial activity, achieving nearly complete inhibition of E. coli and >90% inhibition of S. aureus at 50 mg/L, while maintaining high HaCaT cell viability at the selected working concentration. The resulting Sericin-AgNPs/PVA hydrogel incorporating HGF and KGF-2 (SAP-HK) supported keratinocyte proliferation and migration in vitro and did not induce a detectable pro-inflammatory response in RAW264.7 macrophages. In a full-thickness diabetic murine wound model, SAP-HK treatment achieved a wound healing rate of approximately 94% by day 14, compared with approximately 55–57% in the PBS and SAP groups, and was accompanied by qualitative histological features of epidermal regeneration, granulation tissue formation, and collagen deposition. Overall, SAP-HK provided antibacterial protection and growth-factor-associated regenerative support within a physically cross-linked composite dressing platform for diabetic wound repair.