title: Coating independent cytotoxicity of citrate- and PEG-coated silver nanoparticles on a human hepatoma cell line.
abstract: The antibacterial potential of silver nanoparticles (AgNPs) resulted in their increasing incorporation into consumer, industrial and biomedical products. Therefore, human and environmental exposure to AgNPs (either as an engineered product or a contaminant) supports the emergent research on the features conferring them different toxicity profiles. In this study, 30nm AgNPs coated with citrate or poly(ethylene glycol) (PEG) were used to assess the influence of coating on the effects produced on a human hepatoma cell line (HepG2), namely in terms of viability, apoptosis, apoptotic related genes, cell cycle and cyclins gene expression. Both types of coated AgNPs decreased cell proliferation and viability with a similar toxicity profile. At the concentrations used (11 and 5μg/mL corresponding to IC50 and ~IC10 levels, respectively) the amount of cells undergoing apoptosis was not significant and the apoptotic related genes BCL2 (anti-apoptotic gene) and BAX (pro-apoptotic gene) were both downregulated. Moreover, both AgNPs affected HepG2 cell cycle progression at the higher concentration (11μg/mL) by increasing the percentage of cells in S (synthesis phase) and G2 (Gap 2 phase) phases. Considering the cell-cycle related genes, the expression of cyclin B1 and cyclin E1 genes were decreased. Thus, this work has shown that citrate- and PEG-coated AgNPs impact on HepG2 apoptotic gene expression, cell cycle dynamics and cyclin regulation in a similar way. More research is needed to determine the properties that confer AgNPs at lower toxicity, since their use has proved helpful in several industrial and biomedical contexts.
authors.affiliation: CESAM & Laboratory of Biotechnology and Cytomics, Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal. Electronic address: veronicabastos@ua.pt.
authors.forename: Verónica
authors.initials: V
authors.lastname: Bastos
authors.affiliation: CESAM & Laboratory of Biotechnology and Cytomics, Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: José M P
authors.initials: JMP
authors.lastname: Ferreira-de-Oliveira
authors.affiliation: CICECO - Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Carrola
authors.affiliation: CICECO - Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Ana L
authors.initials: AL
authors.lastname: Daniel-da-Silva
authors.affiliation: CICECO - Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Iola F
authors.initials: IF
authors.lastname: Duarte
authors.affiliation: Department of Biology, Faculty of Sciences, University of Porto, 4169-007 Porto, Portugal. Electronic address: csantos@fc.up.pt.
authors.forename: Conceição
authors.initials: C
authors.lastname: Santos
authors.affiliation: CESAM & Laboratory of Biotechnology and Cytomics, Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Helena
authors.initials: H
authors.lastname: Oliveira
mesh_terms: D000900:Anti-Bacterial Agents / Q000633:toxicity*; D006528:Carcinoma, Hepatocellular; D045744:Cell Line, Tumor; D019343:Citric Acid / Q000633:toxicity*; D015386:Hazardous Substances / Q000633:toxicity*; D006801:Humans; D008113:Liver Neoplasms; D053768:Metal Nanoparticles / Q000633:toxicity*; D011092:Polyethylene Glycols / Q000633:toxicity*; D012834:Silver / Q000633:toxicity*
chemical_list: D000900:Anti-Bacterial Agents; D015386:Hazardous Substances; D019343:Citric Acid; D012834:Silver; D011092:Polyethylene Glycols
keywords: Citrate; Cytotoxicity; HepG2 cells; Nanotoxicology; Poly(ethylene glycol) (PEG); Silver nanoparticles (AgNPs)