Carboxymethyl chitosan/oxidized inulin-based hydrogels crosslinked by Schiff base and gallium-gallic acid coordination for sterilization and wound infection repair

In this study, we formulated a series of multifunctional hydrogels, namely Ga 3+ -GA-CMCS-Oin hydrogels (GGCO), leveraging Schiff base reactions and metal-polyphenol coordination. These GGCO hydrogels were synthesized using oxidized inulin (Oin) and gallic acid-modified carboxymethyl chitosan (GA-CMCS) as key bio-based components, and the crosslinking was achieved through Schiff base bonds between Oin’s aldehyde groups and GA-CMCS’s amino groups, eliminating the need for additional crosslinking agents. Moreover, the phenolic hydroxy groups on GA formed metal-polyphenol coordination bonds with Ga 3 ⁺, endowing the hydrogels with potent antibacterial properties and photothermal conversion capabilities. GGCO hydrogels demonstrated exceptional multifunctionality, including superior self-healing, strong adhesion, pH sensitivity, biodegradability, and antioxidant activity. Antibacterial assessments highlighted GGCO’s photothermal antibacterial efficacy, reaching a sterilization rate as high as 99.7%. In a mouse infectious wound model, GGCO hydrogels effectively eradicated bacteria, mitigated inflammatory responses, and accelerated wound healing. Histological analysis further underscored the potential of these multifunctional GGCO hydrogels for advanced wound care solutions.