Light-activated polysaccharide hydrogels: Structural regulation, gelation principle, controlled release property and therapeutic mechanism for osteoarthritis repair.

BACKGROUND: Osteoarthritis (OA) is a degenerative condition primarily manifested through joint pain. Traditional delivery systems often exhibit numerous side effects. In recent years, light-activated polysaccharide hydrogels with rapid and stable phase transition properties and excellent biocompatibility have served as an ideal platform for controllable local drug delivery and effective tissue regeneration in OA treatment. However, a systematic review of light-activated polysaccharide hydrogels for OA repair is still lacking.

SCOPE AND APPROACH: This review firstly summarizes the structural regulation and gelation principle of light-activated polysaccharide hydrogels for OA repair, followed by their controlled release property, and therapeutic mechanism.

KEY FINDINGS AND CONCLUSIONS: This review establishes a framework for light-activated polysaccharide hydrogels in OA repair. In the design of light-activated polysaccharide hydrogels, the density of polysaccharide functional groups (i.e., -NH2, -OH and -COOH) governs the grafting of light-responsive moieties, which in turn dictates crosslinking density and mechanical properties. The photothermal materials and modifications to the polysaccharide hydrogels collaboratively regulate release kinetics, while the different delivery formats could meet specific therapeutic requirements in OA treatment. However, more development and research are needed to extensively explore long-term safety, mechanical strength, and photocuring depth of these light-activated polysaccharide hydrogels.