Multifunctional hydrogels loaded with tannic acid-modified MXene for synergistic photothermal/pharmacological treatment of infected wounds caused by drug-resistant bacteria.

The development of advanced dressings capable of integrating multiple therapeutic modalities represents a promising strategy for promoting the healing of complex infected wounds. Herein, we developed a multifunctional hydrogel dressing (OC-MT-AG) based on tannic acid-modified MXene (MT) and ampicillin/ glutamine (AG) for the synergistic treatment of drug-resistant bacterial-infected wounds. The hydrogel was primarily formed by dynamic Schiff base bonds between the aldehyde groups of oxidized hyaluronic acid (OHA) and the amino groups of carboxymethyl chitosan (CMCS). The incorporation of MT nanosheets not only significantly shortened the gelation time and enhanced tissue adhesion but also endowed the hydrogel with excellent reactive oxygen species (ROS) scavenging ability. In vitro cell experiments demonstrated that OC-MT-AG exhibited good cytocompatibility and promoted cell migration, angiogenesis, and anti-inflammatory responses. Moreover, under 808 nm near-infrared (NIR) irradiation, MT nanosheets and AG exhibited a synergistic antibacterial effect, resulting in the efficient eradication of drug-resistant bacteria. In a full-thickness skin defect model infected with ampicillin-resistant Escherichia coli (AREC), the combination of the hydrogel with NIR irradiation rapidly eliminated bacteria, alleviated inflammation, and significantly accelerated wound closure. This study provides a versatile and practical material platform for the synergistic treatment of stubborn bacterial infections.