pH-responsive nanozymes: multifunctional platforms for biomedical catalysis toward clinical translation

As an emerging class of smart nanomaterials, pH-responsive nanozymes are capable of realizing dynamic regulation of catalytic activity according to microenvironmental acidity and alkalinity. The material system encompasses noble metals, metal oxides, metal sulfides, carbon-based nanozymes, and metal-organic frameworks. Through engineering strategies such as surface ligand modification, heterogeneous atom doping and core-shell structure design, these nanozymes can achieve precise response to complex biological microenvironments, and show unique catalytic properties in the lesion site with specific pH. In recent years, pH-responsive nanozymes have been applied in various biomedical fields, such as tumor therapy, antimicrobial, wound healing, and anti-inflammation, to enhance therapeutic efficacy through controlled activation and targeted drug delivery. However, they still face many challenges in clinical translation, such as <i>in vivo</i> stability, toxicity assessment and precise regulation of activity. This paper reviews the research progress of pH-responsive nanozyme therapeutic systems and discusses the potential and challenges of integrating them with other nanotechnologies and therapeutic modalities, aiming to provide a reference and outlook for promoting their wider application in clinical diseases.