Metal-polyphenol nanomedicines for malignant tumor therapy

Malignant tumor is still one of the most critical diseases in clinic. Current therapeutic strategies include surgery, chemoradiotherapy, targeted therapy, and immunotherapy. Nevertheless, the development of novel drugs with superior efficacy and reduced drug toxicity remains a goal for researchers. The rise of nanomedicine has injected new momentum into oncology treatment. Among nano-platforms, metal-polyphenol materials can be engineered into nanodots, nanospheres or network structures, which can encapsulate or load metabolic enzyme inhibitors and chemotherapeutics, enabling precision therapy through both passive and active targeting. Furthermore, these metal-polyphenol nanocomposites frequently integrate the functionalities of chemodynamic therapy, photothermal therapy and photodynamic therapy, synergistically amplifying antitumor effects. To date, however, curcumin, tannic acid, and epigallocatechin gallate have dominated the metal-polyphenol nanomaterials, whereas complex metal-polyphenol nanomaterials remain scarce. Accordingly, this review systematically summarizes the advantages and mechanisms of metal-polyphenol systems categorized by metal species, dissects the antitumor mechanisms of polyphenols, and outlines the substantial potential of metal-polyphenol nanomaterials for treating malignancies.