Genotoxicity and cytotoxicity assessment of graphene oxide nanosheets on HT29 cells

Background: Graphene and graphene-related materials are broadly applied for biomedical purposes due to their unique properties. However, little information is available on their toxicity and biocompability, thus it is necessary to assess their safety. We investigated the cytotoxic and genotoxic effects of graphene oxide nanosheets (GOs) on HT29 cells. Methods: GOs were synthesized by oxidation of natural graphite flakes according to the modified Hummers method. GOs were characterized using IR spectroscopy and TEM. Cytotoxicity and genotoxicity of GOs on HT29 cells were evaluated in the range of 10-250 μg/ml after 24, 48 and72 h of treatment using MTT assay and in the range of 10-50 μg/ml after 48h by micronucleous assay. Results: The results of IR indicate that the graphite is successfully oxidized. The GOs were found to be 3-6 µm in length and ≤1nm in diameter by TEM. The half maximal inhibitory concentration (IC50) in different doses were calculated at 50 µg/ml by trypan blue dye exclusion assay. The results of MN assay showed a significant increase in DNA damage and MN formation in GOs treated samples as compared with the control sample (p 0.05). Conclusion: Concentration, shape, time and physicochemical properties GOs like size, shape, agglomeration rate and surface chemistry play important roles in inducing cytotoxicity and genotoxicity of treated cells.