MnO₂-Disguised Upconversion Hybrid Nanocomposite: An Ideal Architecture for Tumor Microenvironment-Triggered UCL/MR Bioimaging and Enhanced Chemodynamic Therapy

Upconversion nanoparticles (UCNPs) and MnO2 hybrid theranostic nanoplatform (UCMn) is highly desired; however, the rational design of such UCMn hybrid nanomaterials is still a great challenge. Herein, a simple and versatile strategy for the in situ growth of MnO2 on the surfaces of UCNPs was reported using a sacrificial template method to construct an ideal MnO2-disguised and tumor microenvironment–triggered architecture. Such sophisticated architecture not only achieves activatable magnetic resonance imaging and restorable upconversion luminescence (UCL) imaging with over 100-fold enhancement of UCL in vivo but also significantly improves the efficiency of chemodynamic therapy (CDT) by glutathione depletion- and cisplatin-activation-enhanced •OH generation simultaneously. Additionally, the synergetic effect of CDT and chemotherapy presents excellent therapeutic effect in vivo as compared to either CDT or chemotherapy alone. We believe that the ideal design of the MnO2-disguised upconversion hybrid nanocomposite will provide more revelations on the future research on nanoscale theranostic systems.