A composite hydrogel of chitosan/heparin/poly (γ-glutamic acid) loaded with superoxide dismutase for wound healing.

In chronic wounds, severe oxidative stress hampers the healing of wounds. This study constructed a novel antioxidant-loaded hydrogel for healing diabetic wounds. First, composite hydrogels consisting of chitosan, heparin and poly (γ-glutamic acid) with different ratios were prepared through electrostatic interaction. These hydrogels exhibited good three-dimensional network structures, and the porosity of the hydrogels decreased as the crosslinking density increased. The hydrogels possessed good swelling capacity, and showed typical viscoelastic behavior and good mechanical property in rheological test. Fibroblast proliferation assay demonstrated that the hydrogels were cytocompatible. Then, superoxide dismutase was loaded onto the hydrogel to build a wound dressing with antioxidant property. In diabetic rat models, the dressing proved to accelerate wound healing by promoting wound closure and collagen deposition. In summary, the hydrogel prepared in this study exhibited good physical properties and could promote the repair of chronic trauma in diabetes effectively and therefore is a promising candidate dressing in wound healing.