Achieving enhanced NIR light-induced toxicity via novel hybrid magnetic nanoparticles

Magnetic nanomaterials have been widely used in biomedical fields due to their non-toxicity and versatile functionalities. In this study, we rationally synthesized novel Zn 2+ -doped magnetic nanoparticles via a facile but organic reagent-free hydrothermal route, as well as utilized them to achieve enhanced NIR light-induced toxicity towards cancer cells. By using other metal salts as precursors in the typical synthesis, a series of hybrid magnetic nanoparticles could be obtained with inexpensive inhesion. Upon an 808 nm laser irradiation, Zn 2+ -doped magnetic nanoparticles revealed excellent photothermal effect with high photo-stability and a concentration/time-dependent manner. Cytotoxicity studies of these nanoparticles suggested their low systemic toxicity towards 786-O cells. After efficient endocytosis, Zn 2+ -doped magnetic nanoparticles were mainly accumulated in lysosomes, which caused the persistent release of Zn 2+ ions and the following generation of reactive oxygen species (ROS). Significantly, enhanced generation of ROS was only detected in the group treated with magnetic nanoparticles and a NIR light irradiation because the localized heat could increase the dissolution of magnetic nanoparticles in the acid medium. The combination of toxic ROS and photothermal effect could minimize the dosage of nanoagents and enhance the NIR light-induced toxicity. More importantly, Zn 2+ -doped magnetic nanoparticles showed more toxicity than pure Fe 3 O 4 nanoparticles prepared with a similar route upon the irradiation. Last but not least, our study demonstrated a new concept by using single-phase hybrid magnetic nanoparticles as promising candidates for NIR light-induced cancer treatment and brought more meaningful ideas in the bio-related research.