Cu plasma doping induced Cu@MoS2-PEG nanozymes for highly efficient inhibition of tumor cell multiplication

Producing reactive oxygen species within tumors is one of the main pathways inducing apoptosis or necrosis of malignant tumor cells. However, the active sites of MoS2 nanozyme are mainly the S sites and defects at the edge, while the S sites on the basal plane are inactive, so the inhibitory effect of the MoS2 nanozyme on tumor cells is limited. Herein, it is reported the Cu-doped pegylated MoS2 nanozymes (Cu@MoS2-PEG, denoted CuMPN) were constructed via plasma immersion ion beam system (PIIB). Introducing Cu dopant, not only does it increase the electron density of the CuMPN surface, but also it has a high dispersibility in liquids, which makes it possible to effectively start the in-situ Fenton reaction, which produces a lot of harmful hydroxyl radicals (•OH) specifically in the tumor microenvironment (TME). The in vitro studies had manifested that the designed Cu0.86MPN nanozymes have efficient inhibitory effects on mouse breast cancer cells (4T1 cells) and glioma cells (GL261 cells), meanwhile exhibiting good biosafety against mouse fibroblasts (L929 cells). The use of plasma immersed ion beam systems opens a new path for the development of high efficiency and biosecurity nano-catalytic drugs.