Abstract
The aim of this work was to compare the effects of three commercially available gold nanoparticles (AuNPs) of different sizes (30, 50 and 90 nm) on the viability of normal human dermal fibroblasts (NHDF). In addition, we evaluated protective effect of N-Acetyl-L-cysteine (NAC), total glutathione content (GSH/GSSG), superoxide dismutase (SOD) activity and reactive oxygen species (ROS) production to investigate if oxidative stress was involved in the cytotoxic response of these AuNPs. Although AuNP-induced cytotoxicity was dose and time dependent, nanoparticle size slightly influenced the cytotoxic response of AuNPs assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase. Regarding oxidative parameters, NAC produced no significant protection of NHDF cells against treatment with any of the three AuNPs. Independently on nanoparticle size, GSH/GSSG content was drastically depleted after 24 h of incubation with the three AuNPs (less than 15% in all cases), while no statistically significant changes on SOD activity were reported (approximate to 90% of activity). The three AuNPs also caused a notable increase in the ROS production of NHDF cells. In conclusion, our data suggest that AuNP-induced cytotoxicity in NHDF is mediated by oxidative stress and it is independent of nanoparticle size.