Glucose Oxidase-Loaded Antimicrobial Peptide Hydrogels: Potential Dressings for Diabetic Wound

The wound of diabetic foot is difficult to heal, and in severe cases, diabetic patients have to undergo limb amputation even after wound management. Hyperglycemia-caused vascular dysfunction and serious wound bacterial infection are the two main causes of unhealed diabetic foot ulcers. Therefore, it would be of great benefit to rescue stalled healing in diabetic wound if the blood glucose concentration can be efficiently decreased while controlling the bacterial infection in diabetic wound. Herein, we report glucose oxidase (GOx)-loaded antimicrobial peptide hydrogels and investigate their potential as diabetic wound dressings. The antimicrobial hydrogels are formed by the self assembly of a heptapeptide (IKYLSVN) driven by intermolecular hydrogen bonding and pi-pi stacking interaction. The loaded GOx can convert glucose into hydrogen peroxide (H2O2), thus reducing blood glucose concentration of diabetic patients. At the same time, the produced H2O2 is antimicrobial and can combat bacterial infection in diabetic wound together with the antimicrobial hydrogels. Microscopic morphology observation of hydrogel shows uniform fibers with approximately 40 nm in size. The embedding rate can still reach 90% when the loading rate of the hydrogel loaded glucose oxidase is 12%. GOx is released by the swelling of the hydrogel based on the mechanism of free diffusion, and the cumulative release rate reaches 55%. Moreover, in vitro experiments showed that our GOx-loaded peptide hydrogel exhibits outstanding antimicrobial activity while can efficiently reduce glucose concentration of blood samples, showing great potential as promising diabetic wound dressings.