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

Abstract

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.