Annealing-Cross-Linked Flammulina velutipes Polysaccharide/ZnO Composite Hydrogels with Synergistic Antibacterial-Antioxidant Activities for Accelerated Full-Thickness Wound Healing

Abstract

Polysaccharide-based hydrogels typically suffer from inadequate mechanical strength, uncontrolled swelling, and insufficient inherent bioactivity, which limits their efficacy as wound dressings. To address these issues, annealing-induced physically cross-linked Flammulina velutipes polysaccharide (FVP) hydrogels were systematically optimized, and zinc oxide (ZnO) nanoparticles were incorporated to fabricate dual-functional FVP/ZnO composite dressings. The optimized FVP/ZnO-3 formulation exhibited a compressive modulus of 68.65 kPa and an equilibrium swelling ratio of 1132.75%. Furthermore, it demonstrated broad-spectrum antioxidant activities, with 1,1-diphenyl-2-picrylhydrazyl radical scavenging of 81.35%, hydroxyl radical scavenging of 94.34%, and superoxide anion scavenging of 93.40%, along with potent antibacterial rates of 89.8% against Escherichia coli and 94.7% against Staphylococcus aureus. In a full-thickness skin defect model, the composite dressing achieved 97.12% wound closure by day 14, with enhanced collagen deposition and complete re-epithelialization. This multifunctional FVP/ZnO-3 hydrogel platform represents a promising candidate for further development of advanced dressings for full-thickness skin wounds.