In vitro genotoxicity assessment of nickel(II) oxide nanoparticles on lymphocytes of human peripheral blood.

The current study was intended to elucidate the cytotoxicity, genotoxicity ability of nickel oxide (NiO) nanoparticles (NPs) and assessment of preliminary mechanism of the toxicity. Characterization studies showed that NiO-NPs have a particle size of 17.94 (±3.48) nm. The particle size of the NPs obtained by dynamic light scattering method in Milli-Q and RPMI 1640 media was 189.9 (±17.1) and 285.9 (±19.6) nm, respectively. The IC50 concentration for NiO-NPs after 24 hours of treatment was estimated as 23.58 µg/mL. Comet and cytokinesis-block micronucleus assays revealed a significant dose- and time-dependent genotoxic potential of NiO-NPs. Morphological assessment of the lymphocytes upon exposure to NiO-NPs showed that the mechanism of toxicity was apoptosis. Reactive oxygen species analysis and lipid peroxidation patterns were aligned with the cytotoxicity and genotoxicity endpoints. Thus, the preliminary mechanism of NiO-NPs for cytotoxicity on lymphocytes was assumed to be oxidative stress-mediated apoptosis and DNA damage. Furthermore, these NiO-NPs are considered a potentially hazardous substance at environmentally significant levels. Further investigations are suggested to understand the immunotoxic effects of NiO-NPs.