Modulation of Hypoxia in Solid Tumor Microenvironment with MnO 2 Nanoparticles to Enhance Photodynamic Therapy

Hypoxia not only promotes tumor metastasis but also strengthens tumor resistance to therapies that demand the involvement of oxygen, such as radiation therapy and photodynamic therapy (PDT). Herein, taking advantage of the high reactivity of manganese dioxide (MnO 2 ) nanoparticles toward endogenous hydrogen peroxide (H 2 O 2 ) within the tumor microenvironment to generate O 2 , multifunctional chlorine e6 (Ce6) loaded MnO 2 nanoparticles with surface polyethylene glycol (PEG) modification (Ce6@MnO 2 ‐PEG) are formulated to achieve enhanced tumor‐specific PDT. In vitro studies under an oxygen‐deficient atmosphere uncover that Ce6@MnO 2 ‐PEG nanoparticles could effectively enhance the efficacy of light‐induced…