Bimetallic oxide Cu1.5Mn1.5O4 cage-like frame nanospheres with triple enzyme-like activities for bacterial-infected wound therapy

Copper-based nanomaterials with intrinsic enzyme-like activity have shown increasing potential as new broad-spectrum antibiotics. However, due to its low catalytic activity, poor glutathione (GSH) depletion capacity, and complex material design, their feasibility is still far from satisfactory. Herein, bimetallic oxide Cu1.5Mn1.5O4 cage-like frame nanospheres (CFNSs) were successfully prepared by a two-step approach for the first time, including gas-assisted soft template solvothermal preparation of Cu-Mn hydroxide hollow sphere (Cu-Mn-OH HSs) precursors, and then calcination to synthesize Cu1.5Mn1.5O4 CFNSs. This ingenious, simple, and rapid material synthesis strategy could obtain well-dispersed and extremely uniform Cu1.5Mn1.5O4 CFNSs with a special mesoporous cavity structure, making its performance close to the requirements of practical applications. Interestingly, the as-prepared Cu1.5Mn1.5O4 CFNSs showed enhanced triple enzyme-like activities (oxidase-, peroxidase-, and glutathione peroxidase-like), which could significantly promote the generation of reactive oxygen species (ROS) due to the increased exposure of active edge sites. Cu1.5Mn1.5O4 CFNSs could effectively kill bacteria by combining OXD-like, POD-like, and GSH-Px-like nanozyme activities. More importantly, in vivo wound healing showed that Cu1.5Mn1.5O4 CFNSs could be conveniently used for wound disinfection. In addition, Cu1.5Mn1.5O4 CFNSs exhibited excellent biosafety without observable toxicity or side effects in mice. This work emphasizes the potential application of bimetallic oxides with triple enzyme-like activities in antibacterial therapy.