A drug delivery system based on the palladium and manganese dioxide composite (FP-Pd@MnO2) is designed and prepared for the first time. The FP-Pd@MnO2 allows doxorubicin (DOX) loading as high as 58% in weight. The rapid release of DOX from FP-Pd@MnO2 is regulated via pH reduction, ascending glutathione concentration, and near-infrared (NIR) stimulus, which is advantageous to control drug release in the tumor site. The photothermal effect of FP-Pd@MnO2 with wide and strong NIR optical absorbance is positively correlated with its concentration. As irradiated with an 808 nm laser, MDA-MB-231 cells and its tumor on mice with FP-Pd@MnO2/DOX administration are significantly suppressed, corroborating the preferable curative effect of combined photothermal therapy and chemotherapy with this agent.
Keywords: chemotherapy; drug delivery; manganese dioxide; palladium; photothermal therapy.