Title: The effect of ZnO NPs on genotoxicity and cell death using the optimum dispersion solution of breast cancer cell lines MCF-7

Abstract

However, the number of in vitro studies are being published regarding the cytotoxicity of nanomaterials is on the increase, the components of the media for toxicity assays have often varied according to the needs of the scientists. Our aim for this study was to: (1) evaluate the influence of serum—in this case, fetal bovine serum FBS, Phosphate Buffer Saline PBS, water for injection, without fetal bovine serum FBS, in a cell culture medium on the toxicity of nano-sized (20–30 nm) ZnO on human breast cancer cell line (MCF-7) and (2) use very small dose that make 50% of cancer cell death after treatment in order to the normal cells can get rid of it and be safe on body normal cells. (3) by using the optimal disersion solution: studying the genotoxicity of ZnO NPs on MCF-7. Dispersion solution is effective factor of cell viability in presence of ZnO NPs as a treatment. The nano sized ZnO exhibited their highest toxicity when exposed to Phosphate buffer saline, in contrast to exposure in media containing 10% serum. This mainly comes from the absence of protein protection, and lower cell growth rate, but also that when we used sterilized water for injection as the dispersion solution it has an observed toxicity and a negative osmotic effect on cells that make cells increase till exploding. So when we used media FBS free as a dispersion solution the toxicity of ZnO NPs is nearly the same of PBS which made us recommended using media FBS free as an optimum dispersion solution that has a great effect on DNA strand breaks in eukaryotic cells using comet assay; DNA damage that representing with the comet tail confirm the ability of ZnO NPs not of cancer cell death only but for disturbance the proliferation by its genotoxicity effect.