Multifunctional polysaccharide/metal/polyphenol double-crosslinked hydrogel for infected wound

Bacterial-infected wounds present a significant challenge in the medical field, posing a severe threat to public health. Traditional wound dressings have limited efficacy in treating bacterial-infected wounds, and antibiotics suffer from cytotoxicity and drug resistance. Consequently, an urgent requirement exists for developing multifunctional wound dressings capable of providing superior antimicrobial activity and expediting wound repair. In recent years, chitosan-based natural polysaccharide hydrogels have garnered attention for their biocompatibility, antimicrobial properties, and ability to aid in hemostasis. This study presents the development of a multi-functional, bi-dynamic network hydrogel for the treatment of wounds infected with bacteria. The hydrogel consists of a backbone of chitosan grafted with chlorogenic acid (CA-ECS), oxidized pullulan polysaccharides (OP), and zinc ions (Zn²⁺). The CA-ECS/OP/Zn²⁺ hydrogel displayed strong adhesion, good injectability, and high mechanical strength and was biodegradable and biocompatible. Furthermore, adding Zn²⁺ and CA enhanced the hydrogel's mechanical properties and antioxidant and antimicrobial activities. In a rat model of full-thickness skin wounds infected with S. aureus, the CA-ECS/OP/Zn²⁺ hydrogel demonstrated great anti-inflammatory, angiogenic, and folliculogenic properties, resulting in accelerated wound healing. The CA-ECS/OP/Zn²⁺ hydrogel has great potential for treating bacterial-infected wounds.