A pH-responsive geniposidic acid-loaded chitosan/dialdehyde carboxymethyl cellulose Schiff base hydrogel for...

Development of pH-responsive wound dressing with effective drug release and ideal therapeutic efficacy remains a significant challenge during skin wound repair. In this study, a pH-responsive geniposidic acid-loaded chitosan/dialdehyde carboxymethyl cellulose (CS/DA-CMC/GPA) Schiff base hydrogel was synthesized and characterized. The mechanical properties, antioxidant capacity, degradability, rheological properties, swelling behavior, drug release behavior, antibacterial properties, and cell cytotoxicity of the wound dressing were systematically studied. The results showed the hydrogel has weak tensile and compressive properties, but high adhesive strength. It exhibited the highest swelling ratio and drug release amount at pH 7, which can be described well by second-order kinetics and Higuchi model, respectively. Compared to E. coli, the wound dressing has a more prominent inhibitory effect against S. aureus. Moreover, the wound healing performance was further examined in mice full-thickness wound model. After 11 d, the wound healing rate exceeded 95%. Finally, histopathological observation and immunohistochemical staining confirmed that the hydrogel dressing effectively promoted cell regeneration and wound repair, indicating its excellent performance for accelerating wound healing. This study highlights an efficient approach for designing novel pH-responsive wound dressing in biomedical application.