Determination of TiO₂, ZrO₂, and Al₂O₃Nanoparticles on Genotoxic Responses in Human Peripheral Blood Lymphocytes and Cultured Embyronic Kidney Cells

Abstract

In this study a genotoxic evaluation of titanium dioxide (TiO2, 2.3 nm), zirconium oxide (ZrO2, 6 nm), aluminum oxide (Al2O3, 16.7 nm) nanoparticles (NP) and their ionic forms was conducted using human peripheral blood lymphocytes and cultured human embryonic kidney (HEK293) cells by means of a modified alkaline comet assay with/without the formamidopyrimidine-DNA glycosylase (Fpg) and endonuclease III (Endo III) enzymes. Modifications to the comet assay by using lesion-specific endonucleases, such as Endo III and Fpg, detect DNA bases with oxidative damage. Both human peripheral blood lymphocytes and cultured embryonic kidney cells were incubated with TiO2, ZrO2, or Al2O3 NP at concentrations of 1, 10, or 100 μg/ml. Our results showed no significant induction in DNA damage by the comet assay with/without the Endo III and Fpg enzymes at all concentrations of ZrO2 and Al2O3. In the case of TiO2 NP only the highest concentration of 100 μg/ml significantly induced a genotoxic response. Data thus indicate that both ZrO2 and Al2O3 NP were not genotoxic in our system and in the case of TiO2 the lowest-observed-adverse-effect level (LOAEL) for genotoxicity was 100 μg/ml. Evidence indicates that these metallic NP are considered safe in light of the fact that no genotoxicity was noted with ZrO2 and Al2O3 and that the highest TiO2 concentration is not environmentally relevant.

Critical issues in genotoxicity assessment of TiO2 nanoparticles by human peripheral blood mononuclear cells

“…Ghosh et al () reported an increase only at the lowest dose (25 μg ml −1 ) in PBMCs treated for 3 hours with TiO 2 (crystalline phase not reported) of 50 nm size. Conversely, Demir, Burgucu, Turna, Aksakal, and Kaya () observed an increase only at the highest dose tested (100 μg ml −1 ) after treatment of PBMCs for 3 hours with TiO 2 NPs of 2.3 nm size (crystalline phase not reported). Finally, Hackenberg et al () failed to observe any DNA damage increase in PBMCs after 24 hours of treatment with 20–200 μg ml −1 anatase NPs (<25 nm).…”

Interaction of Nanoparticles with Blood Components and Associated Pathophysiological Effects

“…Peripheral blood lymphocytes died after exposure to nanoparticles containing silicon and carbon nanotubes, an effect that was dependent on the concentration of the nanoparticles employed [51,52]. TiO 2 , ZrO 2 , and Al 2 O 3 nanoparticles did not damage these cells' DNA at concentrations of 1, 10, and 100 μg/mL [53]. Nanoparticle size seems to influence toxicity.…”

Toxicity of cadmium nanoparticles toBacillus subtilis

“…Major concerns are coming up due to the release of nanosized Cd particles, especially cadmium oxide nanoparticles (CdO NPs) and cadmium sulfide nanoparticles (CdS NPs) from the industries involved in manufacturing quantum dots for biomedical usage (Bentolila et al 2005;Blum et al 2012;Yang et al 2012). Synthesized metal NPs are now being released into the environment in many ways and are emerging as potential environmental contaminants (Oberd€ orster, Oberd€ orster, and Oberd€ orster 2005; Thill et al 2006;Horst et al 2010;Demir et al 2013;Park 2013). Thus, investigation for understanding the toxicological impact of released NPs in the environment is warranted.…”