Toxicological Effects of Titanium Dioxide Nanoparticles: A Review of In Vivo Studies

Table 9

In vivo studies that investigated the genotoxic effects of TiO₂ NPs.

Genotoxicity
References	Crystal phase composition (particle size in nm)	Type of exposure	Type and number of animals	Results
Rehn et al., 2003 [147]	P25 Degussa TiO2 (~20); T805 TiO2 (~20)	Intratracheal instillation: 0.15–1.2 mg TiO2.	30 female Wistar rats per group	Inflammatory action: TCC, AMs, NEUs, TPC, phosphatidylcholine, TNF-α increased.; Genotoxicity: no changes in 8-oxoGua levels.
Trouiller et al., 2009 [148]	P25 Degussa TiO2 (21)	Oral administration: 5 mL of 60–600 μg/mL TiO2 for 5 consecutive days. Pregnant dams: supplemented TiO2 drinking water for 10 days at a concentration of 300 μg/mL.	5 C57Bl/6Jp^un/p^un mice per group	Inflammatory action: blood TNF-α, IFN-γ, KC increased.; Genotoxicity: increase in DNA deletion in in utero treated mice (eyespots per RPE); DNA double strand breaks in bone marrow cells (γ-H2AX foci formation) and in WBC (comet assay); MN in ERYs; 8-OhdG in liver.

8-OhdG, 8-hydroxy-2′-deoxyguanosine; 8-oxoGua, 8-oxoguanine; AM, alveolar macrophage; ERY, erythrocyte; IFN-γ, interferon- γ; KC, mouse orthologue of interleukin-8; MN, micronuclei; NEU, neutrophil; RPE, retinal pigment epithelium; TCC, total cell count; TiO₂ NPs, titanium dioxide nanoparticles; TNF-α, tumor necrosis factor-α; TPC, total protein content; WBC, white blood cells.