Lauric acid-mediated gelatin/hyaluronic acid composite hydrogel with effective antibacterial and immune regulation for accelerating MRSA-infected diabetic wound healing.

The infected diabetic wound healing is an increasingly severe healthcare problem worldwide. Bacterial infection and the inflammatory microenvironment hinder diabetic wound healing. Meanwhile, the combination of inhibiting bacterial growth and promoting macrophage polarization in the wound microenvironment is beneficial for treating diabetic wounds. Nowadays, hydrogels, as an emerging wound dressing, have great potential to replace or supplement traditional bandages or gauze. Here, glycyl methacrylate gelatin (Gel-Gym), oxidized hyaluronic acid (HA-CHO) and lauric acid (LA) were used to prepare the composite hydrogel (GH/LA) in addressing the clinical dilemma. The hydrogel could withstand 50 % compression deformation, its swelling rate was as low as 18 %, and its adhesion to pig skin reached 14 kPa. Moreover, a diabetic infected wound model was used to evaluate the feasibility of GH/LA hydrogel in vivo. The hydrogels' antimicrobial, anti-inflammatory and prorestitutive potentials were further investigated, and GH/LA showed a therapeutic effect on diabetic wounds. Interestingly, macrophage polarization into the M2 phenotype was significantly enhanced in the presence of GH/LA via GPR40/NF-κB pathway. This study provided a new avenue for treating methicillin-resistant staphylococcus aureus (MRSA) infected diabetic wounds.