A Polysaccharide-Based Iron-Curcumin Carbon Dot Hydrogel Dressing with Photothermal and Nanozyme Catalysis for Infected Wound Healing

The treatment of diabetic wounds remains a significant clinical challenge because of the high risk of bacterial infection, persistent inflammation, and impaired healing. In this study, we developed a polysaccharide-based nanocomposite hydrogel dressing for efficient diabetic wound management. To leverage the structural integrity of chitosan as a polysaccharide backbone, curcumin-derived iron-doped carbon dots (FeCDs) loaded mesoporous silica nanoparticles (MSNs) were embedded in polydopamine-chitosan thermosensitive hydrogel (PCH). The FeCDs nanozyme exhibits peroxidase-like activity, catalyzing the conversion of hydrogen peroxide into bactericidal hydroxyl radicals, whereas the system provides sustained release of antimicrobial agents and shows photothermal performance under NIR irradiation. In vitro studies demonstrated strong antibacterial efficacy. The antibacterial efficacy of FeCDs at 50 μg/mL was 99.1%, 98.2% and 99.0% toward Escherichia coli, Staphylococcus aureus, and Streptococcus mutans, respectively. Furthermore, in a diabetic mouse wound model, the final hydrogel significantly promoted wound closure and reduced bacterial infection. These results highlight the great potential of our hydrogel as a comprehensive therapeutic platform for enhancing diabetic wound healing.