Tumor environment responsive degradable CuS@mSiO2@MnO2/DOX for MRI guided synergistic chemo-photothermal therapy and chemodynamic therapy

Chemo-photothermal therapy and chemodynamic therapy have a great promise for enhanced tumor treatment effect for integration of Reactive Oxygen Species (ROS) and O-2 generation. Hereby, a smart tumor environment (TME) responsive theranostic agent based on CuS@mSiO(2)@MnO2 nanocomposites was fabricated by a facile method. When the nanocomposites entered tumor, the drug release was triggered by mull-model response of NIR irradiation, weak acidity and high glutathione (GSH) in TME. The O-2 and toxic center dot OH were generated from H2O2 in TME through catalyzing by MnO2, which relieved hypoxia and enhanced the effect of chemodynamic therapy (CDT). Meanwhile, the generated Mn2+ in TME was used to monitor the nanocomposites delivery by magnetic resonance imaging (MRI). Also, the excellent photothermal therapy effect could be triggered by NIR irradiation for CuS core. More importantly, the growth of tumors was greatly inhibited by the synergetic chemophotothermal therapy and CDT. This work may open a wide route for tumor environment responsive theranostic, including relieving hypoxia, chemo-photothermal therapy, CDT and MR imaging.