An injectable antibacterial chitosan-based cryogel with high absorbency and rapid shape recovery for noncompressible hemorrhage and wound healing.

Great challenges remain in the effective control of irregular and incompressible deep wound bleeding and the promotion of wound healing after bacterial infection. In this study, cryogels were prepared using an ice template based on chitosan (CS), oxidized gallic acid (OGA) and hemin (HE), which are all green edible materials. The cryogels exhibit rapid blood-triggered shape recovery and a high swelling ratio. The cryogels with 5 mg mL HE (Gel-CS/OGA@HE5) exert excellent photothermal effects. Additionally, the cryogels have excellent cytocompatibility and blood clotting abilities. In the mouse liver injury model and mouse tail amputation model, Gel-CS/OGA@HE5 presents better hemostasis properties than gauze and a gelatin sponge. Moreover, Gel-CS/OGA@HE5 displays excellent healing performance as a wound dressing. Overall, we provide a simple and effective strategy to prepare cryogels for controlling wound bleeding and promoting wound healing.