title: Cytotoxicity and apoptosis induced by silver nanoparticles in human liver HepG2 cells in different dispersion media.
abstract: Silver nanoparticles (Ag NPs) have been widely used in medical and healthcare products owing to their unique antibacterial activities. However, their safety for humans and the environment has not yet been established. This study evaluated the cellular proliferation and apoptosis of Ag NPs suspended in different solvents using human liver HepG2 cells. The ionization of Ag NPs in different dispersion media [deionized water, phosphate-buffered saline (PBS), saline and cell culture] was measured using an Ag ion selective electrode. The MTT assay was used to examine the cell proliferation activities. The effects of Ag NPs on cell cycle, induction of apoptosis, production of reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were analyzed using flow cytometry. The degree of Ag NPs ionization differed with dispersion media, with the concentrations of silver ions in deionized water being the highest in all suspensions. Ag NPs could inhibit the viability of HepG2 cells in a time- and concentration-dependent manner. Ag NPs (40, 80 and 160 µg ml(-1)) exposure could cause cell-cycle arrest in the G2/M phase, significantly increasing the apoptosis rate and ROS generation, and decreasing the MMP in HepG2 cells more sensitive to deionized water than in cell culture. These results suggested that the cellular toxicological mechanism of Ag NPs might be related to the oxidative stress of cells by the generation of ROS, leading to mitochondria injury and induction of apoptosis. It also implies that it is important to assess the physicochemical properties of NPs in the media where the biological toxicity tests are performed.
authors.affiliation: Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, Jiangsu Key Laboratory for Biomaterials and Devices, School of Public Health, Southeast University, No.87 Dingjiaqiao, Nanjing, 210009, China.
authors.forename: Yuying
authors.initials: Y
authors.lastname: Xue
authors.affiliation: Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, Jiangsu Key Laboratory for Biomaterials and Devices, School of Public Health, Southeast University, No.87 Dingjiaqiao, Nanjing, 210009, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, Jiangsu Key Laboratory for Biomaterials and Devices, School of Public Health, Southeast University, No.87 Dingjiaqiao, Nanjing, 210009, China.
authors.forename: Bangyong
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, Jiangsu Key Laboratory for Biomaterials and Devices, School of Public Health, Southeast University, No.87 Dingjiaqiao, Nanjing, 210009, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Gong
authors.affiliation: Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, Jiangsu Key Laboratory for Biomaterials and Devices, School of Public Health, Southeast University, No.87 Dingjiaqiao, Nanjing, 210009, China.
authors.forename: Yanmei
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, Jiangsu Key Laboratory for Biomaterials and Devices, School of Public Health, Southeast University, No.87 Dingjiaqiao, Nanjing, 210009, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Tang
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D003470:Culture Media / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D059565:G2 Phase Cell Cycle Checkpoints / Q000187:drug effects; D056945:Hep G2 Cells; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008099:Liver / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D018570:Risk Assessment; D012834:Silver / Q000737:chemistry / Q000633:toxicity*; D012965:Sodium Chloride / Q000737:chemistry; D012995:Solubility; D012997:Solvents / Q000737:chemistry*; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D003470:Culture Media; D017382:Reactive Oxygen Species; D012997:Solvents; D014867:Water; D012834:Silver; D012965:Sodium Chloride
keywords: HepG2 cells; apoptosis; cytotoxicity; dispersion media; silver nanoparticles