Genotoxicity assessment of titanium dioxide nanoparticles using a standard battery of in vivo assays

As one representative of nanometal oxides, titanium dioxide nanoparticles (TiO₂-NPs) have been widely used, particularly in the food industry. The genotoxicity of TiO₂-NPs has attracted great attention over the years. This study was undertaken to investigate the chromosome and DNA damage effects of TiO₂-NPs (0, 50, 150, and 500 mg/kg BW) using rodent models. After a comprehensive characterization, we conducted a standard battery of in vivo genotoxicity tests, including the chromosomal aberration test (CA), micronucleus (MN) test, and the comet test. The results of all these tests were negative. There were no structural or numerical chromosomal abnormalities in mice bone marrow cells, no increase in the frequency of micronucleated polychromatic erythrocytes in mice bone marrow cells, and no elevation in % tail DNA in rat hepatocytes. This indicated that TiO₂-NPs did not cause chromosomal damage or have a direct impact on DNA. These findings suggested that TiO₂-NPs did not exhibit genotoxicity and provided valuable data for risk assessment purposes.