TY - JOUR
T1 - The influence of Citrate or PEG coating on silver nanoparticle toxicity to a human keratinocyte cell line
AU - Bastos, V.
AU - Ferreira de Oliveira, J. M. P.
AU - Brown, David McAllister
AU - Johnston, Helinor Jane
AU - Malheiro, E.
AU - Daniel-da-Silva, A. L.
AU - Duarte, I. F.
AU - Santos, C.
AU - Oliveira, H.
PY - 2016/5/13
Y1 - 2016/5/13
N2 - Surface coating of silver nanoparticles may influence their toxicity, in a way yet to decipher. In this study, human keratinocytes (HaCaT cells) were exposed for 24 and 48 h to well-characterized 30 nm AgNPs coated either with citrate (Cit30 AgNPs) or with poly(ethylene glycol) (PEG30 AgNPs), and assessed for cell viability, reactive oxygen species (ROS), cytokine release, apoptosis and cell cycle dynamics. The results showed that Cit30 AgNPs and PEG30 AgNPs decreased cell proliferation and viability, the former being more cytotoxic. The coating molecules per se were not cytotoxic. Moreover, Ag+ release and ROS production were similar for both AgNP types. Cit30 AgNPs clearly induced apoptotic death, while cells exposed to PEG30 AgNPs appeared to be at an earlier phase of apoptosis, supported by changes in BAX, BCL2 and CASP-3 expressions. Concerning the impact on cell cycle dynamics, both Cit30 and PEG30 AgNPs affected cell cycle regulation of HaCaT cells, but, again, citrate-coating induced more drastic effects, showing earlier downregulation of cyclin B1 gene and cellular arrest at the G2 phase. Overall, this study has shown that the surface coating of AgNPs influences their toxicity by differently regulating cell-cycle and cell death mechanisms.
AB - Surface coating of silver nanoparticles may influence their toxicity, in a way yet to decipher. In this study, human keratinocytes (HaCaT cells) were exposed for 24 and 48 h to well-characterized 30 nm AgNPs coated either with citrate (Cit30 AgNPs) or with poly(ethylene glycol) (PEG30 AgNPs), and assessed for cell viability, reactive oxygen species (ROS), cytokine release, apoptosis and cell cycle dynamics. The results showed that Cit30 AgNPs and PEG30 AgNPs decreased cell proliferation and viability, the former being more cytotoxic. The coating molecules per se were not cytotoxic. Moreover, Ag+ release and ROS production were similar for both AgNP types. Cit30 AgNPs clearly induced apoptotic death, while cells exposed to PEG30 AgNPs appeared to be at an earlier phase of apoptosis, supported by changes in BAX, BCL2 and CASP-3 expressions. Concerning the impact on cell cycle dynamics, both Cit30 and PEG30 AgNPs affected cell cycle regulation of HaCaT cells, but, again, citrate-coating induced more drastic effects, showing earlier downregulation of cyclin B1 gene and cellular arrest at the G2 phase. Overall, this study has shown that the surface coating of AgNPs influences their toxicity by differently regulating cell-cycle and cell death mechanisms.
KW - Apoptosis
KW - Cell cycle
KW - Citrate-coating
KW - Cytokines
KW - Nanotoxicology
KW - PEG-coating
KW - ROS
KW - Silver nanoparticles
U2 - 10.1016/j.toxlet.2016.03.005
DO - 10.1016/j.toxlet.2016.03.005
M3 - Article
C2 - 27021274
SN - 0378-4274
VL - 249
SP - 29
EP - 41
JO - Toxicology Letters
JF - Toxicology Letters
ER -