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, 30 nm 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 5 mu g/mL corresponding to IC50 and similar to 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 (11 mu g/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. (C) 2016 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.
keywords
EPITHELIAL-CELLS; CAPPING AGENT; LUNG-CELLS; TOXICITY; SIZE; PEGYLATION; MECHANISM; SURFACE; AG; GENOTOXICITY
subject category
Environmental Sciences & Ecology
authors
Bastos, V; Ferreira-de-Oliveira, JMP; Carrola, J; Daniel-da-Silva, AL; Duarte, IF; Santos, C; Oliveira, H
our authors
Ana Luísa Daniel da Silva
Principal Researcher
Helena Oliveira
Post-Doc Fellowship
Iola Melissa Fernandes Duarte
Principal Researcher
Joana Carolina Quintela Carrola
PhD Studentacknowledgements
This work was developed in the scope of the projects CICECO-Aveiro Institute of Materials (Ref. FCT UID/CTM/50011/2013) and CESAM (Ref. FCT UID/AMB/50017/2013), financed by national funds through the FCT/MEC and when applicable co-financed by the European Regional Development Fund (FEDER) under the PT2020 Partnership Agreement. Funding to the project FCOMP-01-0124-FEDER-021456 (Ref. FCT PTDC/SAU-TOX/120953/2010) by FEDER through COMPETE and by national funds through FCT, and the FCT-awarded grants (SFRH/BD/81792/2011; SFRH/BPD/111736/2015; SFRH/BPD/74868/2010) are acknowledged. I.F.D and A.L.D.S. acknowledge FCT/MCTES for the research contracts under the Program 'Investigador FCT' 2014.