Natural Polyphenol–Vanadium Oxide Nanozymes for Synergistic Chemodynamic/Photothermal Therapy.

The selection of suitable nanozymes with easy synthesis, tumor specificity, multifunction, and high therapeutics is meaningful for tumor therapy. Herein, a facile one‐step assembly approach was employed to successfully prepare a novel kind of natural polyphenol tannic acid (TA) hybrid with mixed valence vanadium oxide nanosheets (TA@VOx NSs). In this system, VOx is assembled with TA through metal–phenolic coordination interaction to both introduce superior peroxidase‐like activity and high near infrared (NIR) absorption owing to partial reduction of vanadium from V5+ to V4+. The presence of mixed valence vanadium oxide in TA@VOx NSs is proved to be the key for the catalytic reaction of hydrogen peroxide (H2O2) to.OH, and the corresponding catalytic mechanism of H2O2 by TA@VOx NSs is proposed. Benefitting from such peroxidase‐like activity of TA@VOx NSs, the overproduced H2O2 of the tumor microenvironment allows the realization of tumor‐specific chemodynamic therapy (CDT). As a valid supplement to CDT, the NIR absorption enables TA@VOx NSs to have NIR light‐mediated conversion ability for photothermal therapy (PTT) of cancers. Furthermore, in vitro and in vivo experiments confirmed that TA@VOx NSs can effectively inhibit the growth of tumors by synergistic CDT/PTT. These results offer a promising way to develop novel vanadium oxide‐based nanozymes for enhanced synergistic tumor‐specific treatment. [ABSTRACT FROM AUTHOR]