Genotoxic evaluation of different sizes of iron oxide nanoparticles and ionic form by SMART, Allium and comet assay.

In this study, the genotoxic potential of <50 nm, <100 nm iron oxide (FeO) nanoparticles (IONPs) and ionic form were investigated using the wing somatic mutation and recombination test (SMART) and Allium and comet assays. In the SMART assay, different concentrations (1, 2, 5 and 10 mM) of NPs and ionic forms were fed to transheterozygous larvae of Drosophila melanogaster. No significant genotoxic effect was observed in <100 nm NPs and ionic form, while <50 nm IONPs showed genotoxicity at 1 and 10 mM concentrations. Allium cepa root meristems were exposed to five concentrations (0.001, 0.01, 0.1, 1 and 10 mM) of <50 nm and ionic forms for 4 h and three concentrations (2.5, 5 and 10 mM) for <100 nm of IONPs for 24 and 96 h. There was a statistically significant effect at 96 h at all concentrations of <100 nm IONPs. Similarly, <50 nm of IONPs and ionic forms also showed a statistically significant effect on mitotic index frequencies for all concentrations at 4 h. There was a dose-dependent increase in chromosomal abnormalities for IONPs and ionic form. Comet assay results showed time- and concentration-dependent increases in <100 nm NPs. There was a concentration-dependent increase in <50 nm NPs and ionic form ( p < 0.05). Consequently, the <50 nm of FeO was found toxic compared to 100 nm FeO and ionic form.