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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@VO x NSs). In this system, VO x 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 V 5+ to V 4+ . The presence of mixed valence vanadium oxide in TA@VO x NSs is proved to be the key for the catalytic reaction of hydrogen peroxide (H 2 O 2 ) to . OH, and the corresponding catalytic mechanism of H 2 O 2 by TA@VO x NSs is proposed. Benefitting from such peroxidase-like activity of TA@VO x NSs, the overproduced H 2 O 2 of the tumor microenvironment allows the realization of tumor-specific chemodynamic therapy (CDT). As a valid supplement to CDT, the NIR absorption enables TA@VO x NSs to have NIR light-mediated conversion ability for photothermal therapy (PTT) of cancers. Furthermore, in vitro and in vivo experiments confirmed that TA@VO x 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., (© 2020 Wiley-VCH GmbH.)

Malignant melanoma is a highly aggressive tumor resistant to chemotherapy. Therefore, the development of new highly effective therapeutic agents for the treatment of malignant melanoma is highly desirable. In this study, a new class of polymeric photothermal agents based on poly(N-phenylglycine) (PNPG) suitable for use in near-infrared (NIR) phototherapy of malignant melanoma is designed and developed. PNPG is obtained via polymerization of N-phenylglycine (NPG). Carboxylate functionality of NPG allows building multifunctional systems using covalent bonding. This approach avoids complicated issues typically associated with preparation of polymeric photothermal agents. Moreover, PNPG skeleton exhibits pH-responsive NIR absorption and an ability to generate reactive oxygen species, which makes its derivatives attractive photothermal therapy (PTT)/photodynamic therapy (PDT) dual-modal agents with pH-responsive features. PNPG is modified using hyaluronic acid (HA) and polyethylene glycol diamine (PEG-diamine) acting as the coupling agent. The resultant HA-modified PNPG (PNPG-PEG-HA) shows negligible cytotoxicity and effectively targets CD44-overexpressing cancer cells. Furthermore, the results of in vitro and in vivo experiments reveal that PNPG-PEG-HA selectively kills B16 cells and suppresses malignant melanoma tumor growth upon exposure to NIR light (808 nm), indicating that PNPG-PEG-HA can serve as a very promising nanoplatform for targeted dual-modality PTT/PDT of melanoma., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)