Sprayable alginate hydrogel dressings with oxygen production and exosome loading for the treatment of diabetic wounds

Chronic wound unhealing is a common complication in diabetic patients, which is mainly caused by tissue hypoxia, slow vascular recovery, and a long period of inflammation. Here we present a sprayable alginate hydrogel (SA) dressing consisting of oxygen-productive (CP) microspheres and exosomes (EXO) to promote local oxygen generation, accelerate macrophage towards M2 polarization, and improve cell proliferation in diabetic wounds. Results show that the release of oxygen continues for up to 7 days, reducing the expression of hypoxic factors in fibroblasts. In vivo, the diabetic wounds experiment showed that the CP/EXO/SA dressing apparently accelerated full-thickness wound healing characteristics such as the promotion of wound healing efficiency, rapid re-epithelization, favorable collagen deposition, abundant angiogenesis at the wound beds, and shortened inflammation period. EXO synergistic oxygen (CP/EXO/SA) dressing suggests a promising treatment measure for diabetic wounds.