Tumor microenvironment (TME)-responsive chemodynamic therapy (CDT) mediated by nanozymes has been extensively studied in oral squamous cell carcinoma. However, the low catalytic efficiency due to insufficient H2O2 in the TME is still a major challenge for its clinical translation. Herein, we present an antitumor nanoplatform based on a Mn-Co organometallic framework material (MnCoMOF), which shows peroxidase-like (POD-like) activity, loaded with glucose oxidase (GOx@MnCoMOF), demonstrating the ability of H2O2 self-supply and H2O2 conversion to toxic hydroxyl radicals. The encapsulated GOx efficiently catalyzes glucose into gluconic acid and H2O2 at the tumor site, which can cut off the energy supply to inhibit tumor growth and produce a large amount of H2O2 and acid to compensate for their lack in the tumor microenvironment. The POD-like activity of MnCoMOF can convert H2O2 into hydroxyl radicals and eliminate tumor cells. The nanoplatform exhibits enhanced tumor cell cytotoxicity in a high-glucose medium compared with a low-glucose medium, illustrating sufficient generation of H2O2 from glucose by GOx. The in vivo results indicate that GOx@MnCoMOF has excellent antitumor efficacy and can remodel the immune-suppressive tumor microenvironment. In conclusion, the GOx@MnCoMOF nanoplatform possesses dual enzymatic activities, i.e., POD-like and glucose oxidase, to achieve improved tumor-suppressive efficiency through synergistic starvation and chemodynamic therapy, thus providing a new strategy for the clinical treatment of oral cancer.
Keywords: chemodynamic therapy; glucose oxidase; nanozyme; starvation therapy; tumor microenvironment.