Tuning band gap of MnO2 nanoflowers by Alkali metal doping for enhanced Ferroptosis/phototherapy synergism in Cancer

Abstract Due to the complexity and heterogeneity of tumors, the therapeutic effectiveness of monomodal phototherapy is still limited. As aggressive tumors become more vulnerable to ferroptosis, synergistic ferroptosis/phototherapy has recently emerged as a promising noninvasive anti-cancer strategy. However, desirable phototherapeutic materials exhibiting altogether the required properties including excellent photothermal/photocatalytic performance, long-term biosafety and ferroptosis-inducing capability remains challenging. Herein, the present study proposed a novel strategy to construct a multifunctional nanoplatform based on band gap engineering of semiconductor nanomaterials for synergistic phototherapy. Specifically, a novel alkali-metal doped δ-MnO2 nanoflower with tunable band gap and controllable degradability was developed to realize a highly efficient and safe synergistic ferroptosis/photothermal/photocatalytic therapy. The desirable near-infrared light (NIR)-excited photothermal/photocatalytic properties of MnO2 nanoflowers were endowed and enhanced by narrowing band gap via increasing the doping alkali metal ionic radius (Mg2+