Facile Fabrication of Injectable Multifunctional Hydrogels Based on Gallium-Polyphenol Networks with Superior Antibacterial Activity for Promoting Infected Wound Healing

Multifunctional hydrogels hold significant promise for promoting the healing of infected wounds but often fall short in inhibiting antibiotic-resistant pathogens, and their clinical translation is limited by complex preparation processes and high costs. In this study, a multifunctional hydrogel is developed by combining metal-phenolic networks (MPNs) formed by tannic acid (TA) and gallium ions (Ga³⁺) with chitosan (CS) through a simple one-step method. The resulting CS-TA-Ga³⁺ (CTG) hydrogel is cost-effective and exhibits desirable properties, including injectability, self-healing, pH responsiveness, hemostasis, antioxidant, anti-inflammatory, and antibacterial activities. Importantly, the CTG hydrogels are effective against antibiotic-resistant pathogens due to the unique antibacterial mechanism of Ga³⁺. In vivo studies demonstrate that the CTG hydrogel promotes follicle formation and collagen deposition, accelerating the healing of infected wounds by inhibiting blood loss, suppressing bacterial growth, and modulating the inflammatory microenvironment. These findings highlight the CTG hydrogel's potential as an advanced and translational dressing for enhancing the healing of infected wounds.