Metal-Polyphenol Network Confined Synthesis of Nanozymes with Programmable Oxygen Vacancies for UVB Photodamage...

Conventional sunscreens block ultraviolet B (UVB) but fail to scavenge accumulated reactive oxygen species (ROS), causing severe photodamage. Herein, we develop a room-temperature, aqueous coordination strategy that assembles metal-polyphenol networks (MPNs) to confine in situ nucleation and growth of metal oxide nanozymes. Utilizing tannic acid coordinated ceria (CeO₂-TA) as a model system, we achieve programmable regulation of surface oxygen vacancies (O_v) by adjusting the ligand-to-metal molar ratio. This process involves ligand-to-metal charge transfer (LMCT) mediated interfacial electron redistribution, resulting in significant enhancements in superoxide dismutase (SOD)- and catalase (CAT)-like activities. This "ligand-unit equivalence" design is universally applicable across diverse polyphenols, yielding highly dispersed and catalytically efficient nanozymes. In vivo, topical CeO₂-TA profoundly scavenges UVB-induced ROS, mitigating acute skin inflammation and preserving the extracellular matrix against photoaging. This work establishes a universal and scalable method for the development of O_v engineered nanozymes and promotes their integration into next-generation topical sunscreens.