Enhancing Enzymatic Activity of Glucose Oxidase by Metal–Organic Framework Nanocarriers for Intensive Cascade Catalytic Antibacterial Therapy

Glucose oxidase (GOx) is a natural biological oxidoreductase. Due to its molecular fragility and low operational stability, its enzymatic activity is inevitably inhibited during the immobilization process. To address this issue, herein, GOx is rationally decorated onto iron-based MIL-53­(Fe) metal–organic framework (MOF) nanomaterials with peroxidase-mimic activity by one-step biomimetic mineralization and then coated with polyvinylpyrrolidone (PVP) to construct the GOx@MIL-53­(Fe)@PVP (GMP) cascade catalytic nanosystem. The decorated GOx displays the enhanced catalytic activity for highly effective oxidation of glucose to gluconic acid and H2O2, and the latter is immediately converted into the hydroxyl radical (·OH) by MIL-53­(Fe) under acidic conditions mediated by the produced gluconic acid, thereby achieving chemodynamic therapy (CDT). The results show that GMP has a good cascade catalytic activity and ·OH-generating ability. The antibacterial efficiencies of GMP are determined to be 99.7% for Staphylococcus aureus and 99.8% for Escherichia coli. When GMP is applied to the bacteria-infected wounds of mice, it can effectively eliminate bacteria in the infection sites, accelerate wound healing, and cause negligible damage to the healthy tissues and major organs. The developed GMP possesses satisfactory antibacterial effects in vitro and in vivo, demonstrating great potential in treating bacterial infections.