Glucose Oxidase and Catalase-Loaded ZnS Nanozymes for Regulating the Local Microenvironment and Promoting Wound Healing in Diabetes

Diabetic wound microenvironment has extremely complex continuous hyperglycemia, hypoxia, bacterial infection, and reactive oxygen species accumulation, which lead to slow wound healing. In order to overcome these limitations, glucose oxidase (GOX) and catalase (CAT) were loaded into zinc sulfide (ZnS) particle spheres to construct a high glucose microenvironment responsive treatment strategy with good biocompatibility. When they encounter hyperglycemia and oxidative wound microenvironment at the wound site, the presence of GOX and CAT will be activated by glucose to undergo an effective local cascade catalytic cycle reaction, which decomposes glucose and H2O2 into gluconic acid and O2. They not only reduce the toxic side effects of GOX, improve the hyperglycaemic wound microenvironment, lower the local pH, maintain, and alleviate O2 depletion problems but also trigger the ZnS particle spheres to convert the high glucose microenvironment, which is not conducive to tissue and cell survival, into a favorable environment (zinc gluconate and H2S gas). These products can not only synergistically accelerate cell migration and proliferation in a high glucose environment and play a role in starvation and inhibition of killing bacteria but also enhance the activity of enzyme proteins and achieve long-term effective treatment.