Tumor Microenvironment-Responsive a-MnO۲ as nanotheranostic

Here, alpha manganese dioxide (α-MnO۲) with ultrasensitivebiodegradability in a tumor microenvironment (TME) isgrown on upconversion photodynamic nanoparticles for notonly TME-enhanced bioimaging and drug release, but also forrelieving tumor hypoxia, thereby markedly improving photodynamictherapy (PDT). In this nanoplatform, α-MnO۲ shell isgrown via a facile hydrothermal way on PDT agents. Because ofa-MnO۲ unique mesoporous structure, the drug of doxorubicin(DOX) with a facile hydrothermal way loaded on novel nanoplatform.When used for antitumor application, the α-MnO۲degrades rapidly within the TME, releasing Mn۲+ ions, whichcouple with trimodal imaging of UCNPs to perform a self enhancedimaging. Significantly, the degradation of a-MnO۲ shellbrings an efficient DOX release, and relieve tumor hypoxia bysimultaneously inducing decomposition of tumor endogenous H۲O۲, reduction of glutathione and acidic TME, thus achievinga highly potent chemo-photodynamic therapy.