A biodegradable drug-controlled delivery system based on mesoporous manganese dioxide and poly(dopamine)

Mesoporous manganese dioxide (mMnO 2 ) was first synthesized for the loading of methotrexate (MTX), and then dopamine was in situ polymerized on the surface of the MTX-loaded mMnO 2 (mMnO 2 -MTX) in an alkaline solution to encapsulate the drug in the mesopores of mMnO 2 . Both low pH and glutathione (GSH) can result in the degradation of mMnO 2 and poly(dopamine) (PDA), and thus the delivery of MTX from the mMnO 2 -MTX-PDA can be triggered by low pH and GSH. Near-infrared (NIR) light-responsive delivery of MTX can be achieved owing to the outstanding photothermal conversion capability of PDA; on the other hand, the mMnO 2 -MTX-PDA can be utilized for photothermal therapy under the irradiation of NIR light due to the elevated temperature. The results of cytotoxicity test demonstrate that the pH, GSH, and NIR light tri-responsive drug-controlled delivery system has excellent biocompatibility, while exhibits pronounced growth inhibition against murine breast tumor cell line 4T1.