Cytotoxic, genotoxic and the hemolytic effect of titanium dioxide (TiO2) nanoparticles on human erythrocyte and lymphocyte cells in vitro.

ABSTRACT With the increasing clinical use of titanium dioxide (TiO₂) nanoparticles, a better understanding of their safety in the blood stream is required. The present study evaluates the toxic effect of commercially available TiO₂ nanoparticles (~100 nm) using a battery of cytotoxic, genotoxic, hemolytic and morphological parameters. The cytotoxic effects of TiO₂ nanoparticles in human lymphocyte cells were studied with respect to membrane damage, mitochondrial function, metabolic activity and lysosomal membrane stability. Genotoxicity in lymphocyte cells was quantitated using a comet assay. The mode of cell death (apoptosis/necrosis) was evaluated using PI/Annexin V staining. TiO₂ nanoparticles were also evaluated for their hemolytic properties, osmotic fragility and interaction with hemoglobin. Human erythrocyte cells were studied for morphological alterations using atomic force microscopy (AFM). Results suggest that the particles could induce a significant reduction in mitochondrial dehydrogenase activity in human lymphocyte cells. Membrane integrity remained unaffected by nanoparticle treatment. DNA damage and apoptosis were induced by TiO₂ nanoparticles in a dose-dependent manner. A study on human erythrocyte cells revealed a hemolytic property of TiO₂ nanoparticles characterized by spherocytosis and echinocytosis. Spectral analysis revealed a hemoglobin TiO₂ nanoparticle interaction. Our in vitro study results suggest that commercially available blood contacting nanoparticles (TiO₂ nanoparticle) should be carefully evaluated for their toxic potential. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]