Research progress on modified chitosan hydrogels for tissue repair and regeneration

Tissue repair and regeneration have long been core challenges in biomedical, and the development of functional biomaterials is crucial to addressing these issues. Chitosan, a natural polysaccharide derived from chitin, has garnered significant attention due to its antibacterial activity, antioxidant activity, biocompatibility, biodegradability, and low immunogenicity. However, unmodified chitosan hydrogels exhibit inherent limitations, such as low mechanical strength, rapid degradation rate, poor water solubility, and limited drug controlled-release capability, which restrict their practical applications in tissue repair. Modification can significantly optimize the physicochemical and biological properties of chitosan. This review summarizes recent research progress on modified chitosan hydrogels for tissue repair and regeneration. First, it discusses common modification methods, including chemical, physical, and biological approaches, and introduces computational and AI-Driven Design strategies. Then, it elaborates on the applications of modified chitosan hydrogels in various tissue repair scenarios, such as skin wound healing, bone tissue regeneration, cartilage repair, and neural tissue regeneration. Finally, this review analyzes the current challenges faced by modified chitosan hydrogels and outlines future research directions, aiming to provide theoretical references and technical support for developing high-performance chitosan-based hydrogel materials in tissue engineering.