▎ 摘　　要

Graphene oxide (GO) was prepared by modified Hummers method firstly. In order to improve its water solubility and biocompatibility, 6-armed PEG was grafted onto GO via an amidation process. The size of GO-PEG was less than 250 nm and stability test indicated excellent dispersibility of GO-PEG in water and PBS buffer. Furthermore, oridonin, a widely used cancer chemotherapy drug, is adsorbed onto GO-PEG via blending. The drug loading ratio was determined to be as high as 105%, which was much higher than other common drug carriers. A549 lung cancer cell and MCF-7 breast cancer cell were chosen to study the cytotoxicity of GO-PEG/oridonin, GO-PEG, and free oridonin. The results demonstrated that GO-PEG did not show obvious toxicity (relative cell viability>85%), even cultivated for 48 h at a relatively high concentration of 100 mg/L. Compared to oridonin, the GO-PEG/oridonin nanocarrier shows higher cytotoxicity in A549 and MCF-7 cells.