Construction of oxidized dextran-based pH/ROS responsive hydrogel with live bacterial microcapsules for accelerating diabetic wound healing via reducing inflammatory factors

Diabetic wound (DW) is characterized by chronic inflammation and bacterial infection, making its healing a continuing clinical challenge. Herein, a living bacteria-loaded oxidized dextran hydrogel is successfully fabricated to accelerate wound healing via regulating inflammatory factors. Lactobacillus bulgaricus (LB), as a live microorganism, is encapsulated in the hydrogel via microcapsule technology with gelatin as a substance to reduce secondary infections and ensure the survival of LB. Gelatin microcapsules and oxidized dextran were used to prepare a pH/ROS responsive hydrogel (OPM@GLB) through a Schiff base reaction. Furthermore, mangiferin was also incorporated into the hydrogel by a dynamic borate ester bond to support desirable nutrition for LB. In vitro and in vivo results showed that the OPM@GLB hydrogel exhibited significant antibacterial and anti-inflammatory properties and promoted angiogenesis and collagen deposition to accelerate diabetic wound healing. This study may offer new insights for treating diabetic wound in the clinic.