İnvestigation of genotoxic potential of various sizes Fe2O3 nanoparticles with drosophila melanogaster somatic cells and allium test methods

Nanoparticles are found very common in nature. For instance, proteins exist in almost all biological systems and metal-oxide nanoparticles are easily produced etc. Iron oxide nanoparticles with unique magnetic properties have a high potential to use in several biomedical, bioengineering and in vivo applications, including tissue repair, magnetic resonance imaging, immunoassay, drug delivery, detoxification of biologic fluids, cell sorting, and hyperthermia. Although various surface modifications are being done for making these nonbiodegradable nanoparticles more biocompatible. But their toxic potential is still a major concern. Therefore, it is necessary to use further examination assay systems in order to check nanoparticle's effects. In this study, genotoxic potential of <50 nm, <100 nm Fe2O3 nanoparticles and ionic form were investigated by using Allium test, Comet Assay and wing somatic mutation and recombination test (SMART). In SMART assay, Flare-3 virgin females and mwh males were crossed to get transheterozygous larvae. Different concentrations (1mM, 2 mM, 5 mM and 10 mM) of nanoparticles and ionic form were fed to transheterozygous larvae. No significant genotoxic effect was observd in <100 nm nanoparticles and ionic form while <50 nm Fe2O3 nanoparticles showed genotoxicity at 1 mM and 10 mM concentrations. A. cepa root meristems were exposed with five doses (0,001, 0,01, 0,1, 1, 10 mM) of < 50 nm and ionic form for 4 hour and three doses (2,5, 5, 10 mM) for <100 nm of Fe2O3 nanoparticles for 24 and 96 h. MMS and distilled water were used as a positive and negative control respectively. Mitotic index and mitotic phase frequencies were calculated separately for each concentration and duration. Effect on mitotic phase of <100 nm of Fe2O3 nanoparticles for 24 at 5 mM concentration was observed while there was the statistically significant effect for 96 h at all concentrations of <100 nm of Fe2O3 nanoparticles. Similarly, <50 nm of Fe2O3 nanoparticles and ionic form also showed statistically significant effect on mitotic phase frequencies for all concentrations at 4 h. Comet assay results showed time and concentration dependent increase in <100 nm nanoparticles at 24 and 96 h. Similarly, application of <50 nm nanoparticles and ionic form for 4 h also showed DNA damage as the concentration increased and it was found statistically significant (p <0.05). Consequently, the <50 nm of Fe2O3 was found toxic compared to 100 nm Fe2O3 and ionic form. It could be deduced that nanoparticles especially <50 nm, were more genotoxic because of its smaller size and large surface area.