Antibiotic-free silk sericin hydrogel with antibacterial and antioxidative dual functionalities promotes wound...

Bacterial infections can impede healing and trigger a local or systemic inflammatory response. Thus, there is an urgent need to develop a green antibacterial and antioxidant hydrogel to promote wound healing. In this study, a hydrogel with antibacterial and antioxidant properties was synthesized successfully using tetrakis (hydroxymethyl) phosphonium sulfate (THPS) and silk sericin (SS) as the predominant functional constituents, and polyvinyl alcohol and agarose as the matrix (PATS). PATS's structural composition, biological properties, and unique advantages in treating a rat full-thickness skin defect model were systematically evaluated. THPS and SS were anchored in the PA network through hydrogen bonding interactions and covalent bonds were formed via the Mannich reaction, thereby endowing PATS with remarkable mechanical strength and stability. PATS demonstrated inhibitory effects on the growth of Escherichia coli and Staphylococcus aureus, with inhibition zone diameters of 4.00 ± 1.23 mm and 6.88 ± 1.04 mm, respectively. Furthermore, PATS exhibited effective radical-scavenging properties, achieving 95.35 ± 0.46 % DPPH and 57.44 ± 2.92 % ∙OH radical scavenging activities. In a rat full-thickness skin defect model, PATS treatment demonstrated a healing rate of 85.85 ± 3.65 % by day 14. The observed rapid wound contraction was found to effectively promote wound healing through the reduction of inflammation, the promotion of angiogenesis and folliculogenesis. Consequently, PATS has exhibited favourable outcomes in wound healing and is anticipated to be a viable treatment option.