Enzymatically crosslinked pectin-silk fibroin hydrogel with embedded ZnO@Gallic acid nanoparticles: An injectable,...

A multifunctional hydrogel wound dressing with injectable, self-healing, and antibacterial properties was developed via HRP/H₂O₂-mediated enzymatic crosslinking of pectin and silk fibroin, integrating zinc oxide-gallic acid metal-phenolic network nanoparticles (ZnO@GA NPs). This approach combines enzymatic covalent crosslinking with dynamic metal-phenolic interactions, producing a mechanically stable yet adaptive hydrogel network. The synthesized ZnO@GA NPs displayed uniform spherical morphology (42.3 ± 10 nm), negative surface charge, and high thermal stability, confirming efficient gallic acid functionalization. Incorporating ZnO@GA NPs enabled rapid in situ gelation (<1 min), enhanced antibacterial activity, particularly against Staphylococcus aureus, and provided sustained release of Zn²⁺ ions and gallic acid without cytotoxicity. The nanocomposite hydrogels exhibited reduced swelling and degradation while improving mechanical performance. Notably, the hydrogel containing 3 wt% ZnO@GA NPs achieved an optimal balance of storage modulus, injectability, and self-healing, while significantly enhancing cell viability and collagen deposition. In vivo evaluation in a rat full-thickness wound model demonstrated accelerated wound closure, improved re-epithelialization, organized collagen deposition, and reduced inflammation. Collectively, this study presents a mechanistically integrated enzymatic-metal phenolic hydrogel platform with strong potential for advanced and chronic wound care applications.