Green fabrication and wound repair evaluation of carrageenan-based composite antibacterial hydrogel

Full-thickness skin defects present substantial clinical challenges owing to the complete disruption of normal tissue architecture, elevated susceptibility to microbial infection, and the inherently limited regenerative capacity of damaged skin. Accordingly, the development of injectable biomaterials that integrate antibacterial activity with regenerative functionality is essential for facilitating efficient skin repair. This study presents an environmentally friendly strategy for the construction of a silver nanoparticle-incorporated carrageenan–hyaluronic acid composite antibacterial hydrogel intended for full-thickness skin wound repair. Under visible light, silver ions simultaneously participate in the cross-linking reaction of carrageenan and are reduced to uniformly dispersed silver nanoparticles, thereby endowing the hydrogel with a stable structure and antibacterial activity without the need for exogenous cross-linking agents and chemical reducing agents. The resulting hydrogel exhibited good injectability, high water content, biocompatibility, and biodegradability, and had a broad-spectrum antibacterial effect against both Gram-positive and Gram-negative bacteria. In vitro experiments demonstrated that the hydrogel exhibited excellent cytocompatibility and significantly enhanced cellular activity. Moreover, evaluation in animal models of full-thickness skin defects confirmed that the injectable carrageenan–hyaluronic acid–silver nanohydrogel effectively accelerated wound closure within 14 days. This environmentally friendly, antibacterial polysaccharide-based hydrogel offers a novel strategy for the design of injectable wound dressings and shows promising application prospects in skin wound repair and regenerative medicine.