A Porphyrin-Based Metal-Organic Framework Nanozyme with Superior Peroxidase-like Activity for Combating Antibacterial Infections and Promoting Wound Healing

As an antibacterial agent, H2O2 is widely used to combat pathogenic bacterial infections clinically. To mitigate potential side effects associated with a high dosage of H2O2, it is pivotal to improve its antibacterial efficacy. Herein, a nanoscale porphyrin-based mesoporous metal-organic framework (MOF) nanozyme, Nano-PCN-222(Fe), was readily prepared by a one pot. Nano-PCN-222(Fe) shows a striking peroxidase (POD)-like activity comparable to that of natural enzyme horse radish peroxidase. Such a high POD-like activity of Nano-PCN-222(Fe) nanozyme is primarily attributed to both the monodispersion and the accessibility of single-atom catalytic sites Fe within the framework. As a consequence of its ability to effectively catalyze the decomposition of H2O2 into more toxic hydroxyl radicals, Nano-PCN-222(Fe) shows excellent antibacterial activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria with the assistance of H2O2. Remarkably, only 10 mM H2O2 is sufficient to fully kill E. coli and S. aureus in the presence of Nano-PCN-222(Fe) (10 ppm), which is significantly lower than that used in actual clinical disinfection (166-1000 mM). Moreover, Nano-PCN-222(Fe) could significantly accelerate infected wound healing due to its superior antimicrobial activity. Additionally, no appreciable biotoxicity of Nano-PCN-222(Fe) was observed even though its dosage was up to 30 ppm.