Self-oxygenating, autonomous self-healing dual-physical crosslinked PVA/chitosan/hydrolysed collagen hydrogels for advanced wound management

Abstract

Impaired wound healing in diabetic patients is a significant healthcare concern, often leading to microbial infections and delayed recovery due to the absence of an optimal healing environment. An ideal wound dressing should provide self-oxygenation, self-healing properties, mechanical strength, antimicrobial activity, and biocompatibility, which are crucial factors for cell survival and tissue regeneration. This study developed a dual physically crosslinked hydrogel composed of polyvinyl alcohol (PVA), chitosan (CS), and collagen peptide (Col), incorporating polycaprolactone (PCL)-coated calcium peroxide (CPO) particles. The effects of CPO, borax, and freeze–thaw (FT) cycles on the hydrogel's physicochemical properties and biocompatibility were analyzed. CPO significantly increased dissolved oxygen levels, with 20 mg CPO per 10 g gel providing sustained oxygen release over seven days, while higher CPO concentrations led to an initial burst release. The hydrogel exhibited excellent viscoelasticity and mechanical strength, maintaining elasticity without becoming rigid. Optimizing borax content and FT cycles resulted in a self-healing hydrogel with enhanced mechanical properties. The combination of CPO and CS achieved 100% inhibition of Staphylococcus aureus, demonstrating strong synergistic antimicrobial effects. In vitro biocompatibility was assessed using an MTT assay on hydrogel extracts, revealing excellent cytocompatibility with L929 fibroblasts, with cell viability reaching 107%. Additionally, Calcein-AM/PI live/dead staining of cells cultured directly on the hydrogels confirmed sustained cell adhesion and healthy spindle-like morphology. A scratch wound assay further demonstrated enhanced fibroblast migration, achieving over 95% wound closure within three days. These findings highlight the potential of this composite hydrogel as a multifunctional wound dressing for accelerating wound healing.