Acridine Orange Encapsulated Mesoporous Manganese Dioxide Nanoparticles to Enhance Radiotherapy.

Manganese dioxide (MnO) nanoparticles are a promising type of radiosensitizer for they can catalyze HO decomposition to produce O. Combining MnO nanoparticles with conventional, small molecule radiosensitizers would further enhance radiotherapy (RT) efficacy due to complementary mechanisms of action. However, solid MnO nanoparticles are suboptimal at drug loading, limiting the related progress. Herein we report a facile method to synthesize mesoporous MnO (mMnO) nanoparticles, which can efficiently encapsulate small molecule therapeutics. In particular, we found that acridine orange (AO), a small molecule radiosensitizer, can be loaded onto mMnO nanoparticles at very high efficiency and released to the surroundings in a controlled fashion. We show that mMnO nanoparticles can efficiently produce O inside cells. This, together with AO-induced DNA damage, significantly enhances RT outcomes, which was validated both and . Meanwhile, mMnO nanoparticles slowly degrade in acidic environments to release Mn, providing a facile way to keep track of the nanoparticles through magnetic resonance imaging (MRI). Overall, our studies suggest mMnO as a promising nanoplatform that can be exploited to produce composite radiosensitizers for RT.