Comparative genotoxicity of cobalt nanoparticles and ions on human peripheral leukocytes in vitro

Owing to the increasing development of nanotechnology, there is a need to assess how engineered nanomaterials can interact with living cells. The main purpose of the present study was to assess whether metal cobalt nanoparticles (CoNP 100–500 nm) are genotoxic compared to cobalt ions (Co21). Uptake experiments were carried out by incubat-ing peripheral blood leukocytes (PBLs) with 57Co21 (added to stable Co21 1022 M to obtain concentrations in the range of 1025 to 1024 M) or with 60CoNP for 24 and 48 h. Whereas intracellular Co21 showed slight or no variations over the baseline levels, CoNP were taken up efficiently leading to intracellular CoNP concentrations of 485 6 106.1 and 970 6 99 fg per cell after 24 and 48 h, re-spectively. The genotoxicity end points considered in this study were the frequency of binucleated micronucleate