Cit/CuS@Fe3O4-based and enzyme-responsive magnetic nanoparticles for tumor chemotherapy, photothermal, and photodynamic therapy.

Safe and efficient drug delivery in a controllable fashion, especially remote and repeatable switch of on-demand drug release, is the subject of widespread attention. A kind of magnetic nanoparticles (DOX-Cit/CuS@Fe3O4-NPs) simultaneously consisted of Cit/CuS@Fe3O4 and doxorubicin (DOX) was presented. The drug release from DOX-Cit/CuS@Fe3O4-NPs could be successfully triggered by the presence of gelatinase, showing great promise for tumor-targeted drug release through an enzymatic degradation mechanism. Compared with free DOX, DOX-Cit/CuS@Fe3O4-NPs could not only specially deliver Cit/CuS@Fe3O4 and DOX into MCF-7 cells, but also could greatly improve the quantity of ROS produced in MCF-7 cells under of 980 nm laser irradiation. DOX-Cit/CuS@Fe3O4-NPs also had highly selective accumulation at tumor tissue of S180 tumor-bearing mice, which were along with a magnet near the tumor site. Furthermore, when combined with NIR laser irridation, DOX-Cit/CuS@Fe3O4-NPs showed a higher antitumor efficacy than the individual therapies in vitro and in vivo. This study showed that DOX-Cit/CuS@Fe3O4-NPs could be used as a platform for tumor chemotherapy, photothermal and photodynamic therapy.