Guard against internal and external: An antibacterial, anti-inflammation and healing-promoting spray gel based on lyotropic liquid crystals for the treatment of diabetic wound

The diabetic wound is a prevalent and serious complication of diabetes, which easily deteriorates due to susceptibility to infection and difficulty in healing, causing a high risk of amputation and economic burden to patients. Bacterial infection, persistent excessive inflammation, and cellular and angiogenesis disorders are the main reasons for the difficulty of diabetic wound healing. In this study, glycerol monooleate (GMO) was used to prepare lyotropic liquid crystal hydrogel (LLC) containing the natural antimicrobial peptide LL37 and carbenoxolone (CBX) to achieve antibacterial, anti-inflammation, and healing promotion for the treatment of diabetic wounds. The shear-thinning properties of the LLC precursor solution allowed it to be administered in the form of a spray, which perfectly fitted the shape of the wound and transformed into a gel after absorbing wound exudate to act as a wound protective barrier. The faster release of LL37 realized rapid sterilization of wounds, controlled the source of inflammation, and accelerated wound healing. The inflammatory signaling pathway was blocked by the subsequently released CBX, and the spread of the inflammatory response was inhibited and then further weakened. In addition, CBX down-regulated connexin (Cx43) to assist LL37 to promote cell migration and proliferation better. Combined with the pro-angiogenic effect of LL37, the healing of diabetic wounds was significantly accelerated. All these advantages made LL37-CBX-LLC a promising approach for the treatment of chronic diabetic wounds.