Hydrogen sulfide releasing poly(γ-glutamic acid) biocomposite hydrogel with monitoring, antioxidant, and antibacterial properties for diabetic wound healing

Adverse factors such as high levels of glucose, oxidative stress, inflammation, and bacterial infection impede diabetic wound healing and even worsen wounds. Owing to its outstanding anti-inflammatory and antioxidant properties as well as the potential to promote cell migration and proliferation, hydrogen sulfide(H2S) gas therapy is promising for chronic diabetic wound recovery. In this work, a multifunctional poly(gamma-glutamic acid)(PGA) hydrogel encapsulated with keratin-based H2S donor(KTC), ciprofloxacin(Cip), and anthocyanins(Ant) was developed. The resultant hydrogel was capable of releasing H2S, thereby promoting cell proliferation and enhancing anti-inflammation and antioxidant activity. The release of antibiotic Cip was accelerated under a diabetic wound microenvironment, thereby enhancing the antibacterial activity of the hydrogel. The encapsulated Ant could serve as a pH monitor, sensitively indicating wound pH conditions in situ and indirectly reflecting wound infection. In vivo results in diabetic wound healing suggested that PGA/Ant/KTC/Cip hydrogel reduced inflammation and promoted angiogenesis and collagen deposition, thereby accelerating wound healing.