Genotoxicity of Aluminum Oxide (Al1O3) Nanoparticle in Mammalian Cell Lines

Nanoparticles are small-scale substances (<100 nm) with unique properties, complex exposure and health risk implications. Aluminum oxide (Al2O3) nanoparticles (NP) have been widely used as abrasives, wear-resistant coatings on propeller shafts of ships, to increase the specific impulse per weight of composite propellants used in solid rocket fuel and as drug delivery systems to increase solubility. However, recent studies have shown that nano-sized aluminum (110 nm in diameter) can generate adverse effects, such as pulmonary response. The cytotoxicity and genotoxicity of Al2O3 NP were investigated using the dye exclusion assay, the comet assay, and the mouse lymphoma thymidine kinase (tk(+/-)) gene mutation assay (MLA). IC20 values of Al2O3 NP in BEAS-2B cells were determined the concentration of 273.44 mu g/mL and 390.63 mu g/mL with and without S-9. However IC20 values of Al2O3 NP were found nontoxic in L5178Y cells both of with and without S-9 fraction. In the comet assay, L5178Y cells and BEAS-2B cells were treated with Al2O3 NP which significantly increased 2-fold tail moment with and without S-9. Also, the mutant frequencies in the Al2O3 NP treated L5178Y cells were increased compared to the vehicle controls with S-9. The results of this study indicate that Al2O3 NP can cause primary DNA damage and cytotoxicity but not mutagenicity in cultured mammalian cells.