pH Switchable Nanozyme Platform for Healing Skin Tumor Wound Infected with Drug‐Resistant Bacteria

Abstract

AbstractNanozymes capable of generating reactive oxygen species have recently emerged as promising treatments for wounds infected with drug‐resistant bacteria, possessing a reduced possibility of inducing resistance. However, the therapeutic effect is limited by a shortage of endogenous oxy‐substrates and undesirable off‐target biotoxicity. Herein, a ferrocenyl coordination polymer (FeCP) nanozyme, featuring pH switchable peroxidase (POD)‐ and catalase (CAT)‐like activity is incorporated with indocyanine green (ICG) and calcium peroxide (CaO2) to fabricate an H2O2/O2 self‐supplying system (FeCP/ICG@CaO2) for precise treatment of bacterial infections. At the wound site, CaO2 reacts with water to generate H2O2 and O2. Acting as a POD mimic under an acidic bacterial microenvironment, FeCP catalyzes H2O2 into hydroxyl radicals to prevent infection. However, FeCP switches to CAT‐like activity in neutral tissue, decomposing H2O2 into H2O and O2 to prevent oxidative damage and facilitate wound healing. Additionally, FeCP/ICG@CaO2 shows photothermal therapy capability, as ICG can emit heat under near‐infrared laser irradiation. This heat assists FeCP in fully exerting its enzyme‐like activity. Thus, this system achieves an antibacterial efficiency of 99.8% in vitro for drug‐resistant bacteria, and effectively overcomes the main limitations of nanozyme‐based treatment assays, resulting in satisfactory therapeutic effects in repairing normal and special skin tumor wounds infected with drug‐resistant bacteria.