Injectable shape-adaptive cellulose hydrogel with antibacterial activity for diabetic wound therapy.

Diabetic chronic wounds are chronically trapped in persistent bacterial infection and prolonged inflammation, severely hindering tissue regeneration. However, developing hydrogel dressings that can simultaneously provide effective antibacterial function and reliable biosafety remains a significant challenge. Herein, we report a shape-conformable and antibacterial hydrogel dressing constructed through dynamic coordination between endogenous histidine ligand and low-toxicity Ce3+ for infected diabetic wound repair. Histidine is covalently grafted onto carboxymethyl cellulose to obtain histidine-modified carboxymethyl cellulose, and the hydrogels are rapidly formed by simple mixing with Ce(NO3)3 solution. Reversible coordination between Ce3+ and carboxyl, hydroxyl, and imidazole groups on cellulose chains endow exceptional injectability, rapid self-healing and shape-conformability, enabling conformal filling of irregular wound cavities. Moreover, the hydrogels exhibit antibacterial activity (exceeding 99.99%) against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and methicillin-resistant Staphylococcus aureus (MRSA), primarily by disrupting bacterial membrane integrity. Notably, the hydrogels show favorable cytocompatibility, with no systemic toxicity in major organs. Importantly, the hydrogel can significantly accelerate infected diabetic wound closure by reducing bacterial burden, alleviating inflammation, and promoting tissue remodeling. Overall, this simple and safe strategy provides a promising platform for antibacterial and advanced dressing design for the healing of infected diabetic wounds.