Au/MXene hydrogel with NIR photothermal regulation promotes diabetic wound healing through synergistic induction of reactive oxygen species storms and EGCG release

Antimicrobial hydrogels with NIR and enhanced mechanics benefit diabetic wound healing. • Au/MXene modifies gel network intermolecular interactions, regulating hydrogel mechanics. • NIR-triggered hyperthermia promotes wound healing via ROS/EGCG release. Biological hydrogels are ideal wound dressings due to their moisturizing, biocompatible, and drug delivery properties. Polyvinyl alcohol (PVA) and sodium alginate (Alg)-based injectable hydrogels show great potential in wound repair; however, simple hydrogels lack antimicrobial properties and cannot effectively prevent and control infections. Herein, Au@Ti 3 C 2 -E composites were obtained by anchoring gold nanoclusters on the surface of ultrathin Ti 3 C 2 nanosheets (1.5 nm) and modifying them by grafting epi ­gallocatechin gallate (EGCG). Under 808 nm laser irradiation, Au@Ti 3 C 2 -E@H exhibited good photothermal effects. Interestingly, elevated temperature can act as a “switch” that significantly enhances the Fenton-like catalytic activity of gold nanoclusters (3–5 nm) and promotes the release of EGCG grafted on the surface. The inhibition results showed that Au@Ti 3 C 2 -E@H achieved 94.5% and 93.0% kill rates of Methicillin-Resistant Staphylococcus Aureus (MRSA) and Ampr Escherichia coli ( E.coli ) through higher Reactive Oxygen Species (ROS) generation efficiency and disruption of bacterial biofilms. Molecular biology results showed that Au@Ti 3 C 2 -E@H significantly upregulated Vascular Endothelial Growth Factor (VEGF), Basic Fibroblast Growth Factor (bFGF), Epidermal Growth Factor (EGF) and Platelet Endothelial Cell Adhesion Molecule-1 (CD31) nearly threefold and downregulated Tumor Necrosis Factor-α (TNF-α), Interleukin-6 (IL-6), and Matrix Metalloproteinase-9 (MMP-9) nearly fourfold, which could promote angiogenesis and epithelial repair. After 21 days of the treatment cycle, the diabetic rats achieved a wound healing rate of 99.2%. Au@Ti 3 C 2 -E enhances the mechanical properties and antibacterial effects of hydrogels, synergizing photothermal and nanozyme activities to provide a promising solution for the repair of diabetic wounds infected with drug-resistant bacteria. Download: Download high-res image (168KB) Download: Download full-size image