Artesunate-loaded poly (lactic-co-glycolic acid)/polydopamine-manganese oxides nanoparticles as an oxidase mimic for tumor chemo-catalytic therapy.

Conventional tumor chemotherapy is limited by its low therapeutic efficacy and side effects, which severely hold back its further application as a first-line agent in clinic. To improve the cure efficacy of cancer, nanozyme with enzyme-like activity has now been extensively investigated as a new strategy for tumor treatment. Herein, an anti-tumor platform based on manganese oxides (MnO) modified poly (lactic-co-glycolic acid) (PLGA)@polydopamine (PDA) nanoparticles (PP-MnO NPs) as an oxidase mimic was developed. PP-MnO NPs could not only produce abundant reactive oxygen species to inhibit tumor growth taking advantage of their oxidase-like activity, but also encapsulate and release antitumor drug (artesunate) to function as chemotherapy, achieving remarkable synergistic chemo-catalytic therapeutic effects. As an oxidase mimics, PP-MnO NPs induced the decrease of mitochondrial membrane potential, down-regulation of Bcl-2, as well as activation of Bax and Caspase-3, demonstrating that the apoptosis triggered by PP-MnO NPs was mediated via mitochondrial pathways. Importantly, the artesunate in PP-MnO NPs further promoted this apoptosis. In addition, Mn ions released from PP-MnO NPs facilitated the tumor-microenvironment-specific T1-weighted magnetic resonance imaging. Taken together, this study well clarifies the antitumor mechanism of artesunate-loaded PP-MnO NPs and offer a synergistic chemo-catalytic strategy for tumor theranostics.