Near infrared-II photothermal-promoted multi-enzyme activities of gold-platinum to enhance catalytic therapy.

Bimetallic nanozymes exhibited multi-enzyme activities, but glutathione (GSH) overexpression and weak catalytic capability restricted their catalytic therapeutic performance. Thus, this study developed a smart nanozyme (AuPt@MnO) with a core-shell structure by coating manganese dioxide (MnO) on the gold-platinum (AuPt) nanozyme (AuPt@MnO) surface to enhance catalytic therapy. In this nanozyme, AuPt possessed triple-enzyme activities, i.e., catalase, peroxidase, and glucose oxidase, which greatly improved oxygen, hydroxyl radicals (·OH), and hydrogen peroxide generation, due to cyclic reactions. Moreover, GSH consumption degraded the MnO shell, which then enhanced ·OH generation of Mn. More importantly, the near-infrared-II (NIR-II) photothermal performance of AuPt@MnO with a high conversion efficiency of 38.7 % further promoted multi-enzyme activities and enhanced catalytic therapy. Moreover, combining NIR-II photothermal therapy and enhancing catalytic therapy decreased the cell viability to 10.8 %, and thereby, the tumors were cleared. Thus, the AuPt@MnO smart nanoplatform developed in this study exhibited NIR-II photothermal-promoted multi-enzyme activities and excellent antitumor efficacy, which will be promising for enhancing catalytic therapy.