Bionic sulfated glycosaminoglycan-based hydrogel inspired by snail mucus promotes diabetic chronic wound healing via regulating macrophage polarization.

The treatment of diabetic foot ulcers remains a significant challenge, as their morbidity is increasing while current therapies are expensive and often ineffective. The dried mucus from the snail Achatina fulica promotes diabetic wound healing. Herein, to develop a more controllable and stable wound dressing for diabetic wound treatment, the AFG/StarPEG hydrogel mimicking snail mucus was prepared by covalently coupling of sulfated glycosaminoglycan from A. fulica (AFG) with star-shaped polyethylene glycol (StarPEG) amine. The AFG/StarPEG hydrogel reduced excessive inflammation in wound tissues by decreasing pro-inflammatory cytokines (IL-6, IL-1β, and TNF-α) and increasing anti-inflammatory cytokines (IL-4 and IL-10). Moreover, it promoted the polarization of macrophages to M2 anti-inflammatory type in diabetic wound. By improving transition of diabetic chronic wound from inflammatory phase to proliferative phase, it promoted angiogenesis, collagen deposition and re-epithelialization, and thus tissue regeneration for wound healing. This work provides a convenient and effective dressing for treating chronic diabetic wound.