▎ 摘　　要

Introduction: Graphene oxide nanoparticles have been widely used in industry and biomedical fields due to their unique physicochemical properties. However, comparative cytotoxicity of silver-doped reduced graphene oxide (rGO-Ag) nanoparticles on normal and cancerous liver cells has not been well studied yet. Materials and methods: This study aimed at determining the toxic potential of rGO-Ag nanocomposite on human liver normal (CHANG) and cancer (HepG2) cells. The rGO-Ag nanocomposite was characterized by using different advanced instruments, namely, dynamic light scattering, scanning electron microscope, and transmission electron microscope. Results: The rGO-Ag nanocomposite reduced cell viability and impaired cell membrane integrity of CHANG and HepG2 cells in a dose-dependent manner. Additionally, it induced reactive oxygen species generation and reduced mitochondrial membrane potential in both cells in a dose-dependent manner. Moreover, the activity of oxidative enzymes such as lipid peroxide, superoxide dismutase, and catalase were increased and glutathione was reduced in both cells exposed to rGO-Ag nanocomposite. Pretreatment with N-acetylcysteine inhibited cytotoxicity and reactive oxygen species generation in CHANG and HepG2 cells exposed to rGO-Ag nanocomposite (50 mu g/mL). DNA damage was determined by Comet assay and maximum DNA damage occurred at rGO-Ag nanocomposite (25 mu g/mL) for 24 h. It is also valuable to inform that HepG2 cells appear to be slightly more susceptible to rGO-Ag nanocomposite exposure than CHANG cells. Conclusion: This result provides a basic comparative toxic effect of rGO-Ag nanocomposite on hepatic normal and cancerous liver cells.