An injectable, self-healing carboxymethylated chitosan hydrogel with mild photothermal stimulation for wound healing.

Hydrogels can mimic extracellular matrix and provide a suitable microenvironment for accelerating wound healing. Nevertheless, the complicated wound condition, the disturbance of external forces, and the manufacturing process of the dressing were still difficult problems. An injectable self-healing hydrogel with mild photothermal therapy (MPTT) was developed for wound healing via dynamic Schiff bonds. After covalently incorporating GO-BPEI (branched polyethyleneimine grafting graphene oxide), an observable mechanical strength improvement and photothermal conversion property of GO-BPEI/carboxymethylated chitosan (CMCS) /aldehyde terminated polyethylene glycol (PEG-CHO) (GCP) hydrogel has been witnessed. MPTT induced by near-infrared (NIR) irradiation could accelerate NIH-3 T3 cells proliferation in vitro. Moreover, in vivo wound defect healing and histological analysis suggested that GCP hydrogels incorporated with MPTT significantly accelerated wound healing by improving collagen fibers deposition, enhancing re-epithelialization, and promoting granulation tissue neogenesis. The GCP hydrogels provide a unique route for wound dressing and present new inspirations for complicated wound management.