Table 8.
Summary table of test results of micronucleus and chromosomal aberrations in vivo studies. Studies within the same route of exposure are ordered by the size of the tested material
| Study design | Test material | Results | Reliability/Relevance | Reference |
|---|---|---|---|---|
| Oral | ||||
| MN in bone marrow rats 10–200 mg/kg per bw 30 days | NSC: 2, TiO2 NPs, Anatase 75 ± 15 nm | Negative | 2/limited | Chen et al. (2014) |
| MN and CA in bone marrow mice 200 and 500 mg/kg per bw 90 days | NSC: 4, TiO2 NPs, crystalline form unknown, mean 58 nm | Positive | 2/limited | Chakrabarti et al. (2019) |
| MN in bone marrow mice 10, 50, 100 mg/kg per bw 14 days | NSC: 1, TiO2 NPs Anatase, 20–50 nm | Positive | 1/high | Shukla et al. (2014) |
| CA in bone marrow mice 0.2–0.8 mg/kg per bw 28 days | NSC: 2, TiO2 NPs, Rutile, 21–31 nm | Positive | 2/limited | Manivannan et al. (2020) |
| MN in bone marrow mice 50, 100 and 200 mg/kg bw 60 days | NSC: 2, TiO2 NPs Anatase, 5–12 nm | Positive | 2/limited | Grissa et al. (2015) |
| Intraperitoneal injection | ||||
| MN assay in peripheral blood and in bone marrow mice 250, 500 and 1,000 mg/kg (1st exp.), 500, 1,000 and 1,500 mg/kg bw (2nd exp.) | NSC: 3, TiO2 Anatase > 100 nm | Equivocal | 2/limited | Shelby et al. (1993) |
| Chromosomal aberration in bone marrow mice 625–2,500 mg/kg bw Single administration | NSC: 3, TiO2, Anatase, > 100 nm | Negative | 2/limited | Shelby and Witt (1995) |
| MN in bone marrow mice 500–2,000 mg/kg bw 5 days | NSC: 1 TiO2 NPs, anatase/rutile, 44 nm | Positive | 1/limited | El‐Ghor et al. (2014) |
| MN in bone marrow mice 0.1–3 g/kg bw Single administration | NSC: 2, TiO2 NPs, Rutile, 28.88 nm (XRD) and 5–45 nm (TEM) | Positive | 2/limited | Lotfi et al. (2016) |
| MN in bone marrow mice 9.38–150 mg/kg bw 5 days | NSC: 2, TiO2 NPs Anatase, < 30 nm | Positive | 1/limited | Fadoju et al. (2019) |
| MN in bone marrow mice 10, 100 and 500 mg/kg bw Single administration | NSC: 2, TiO2 NPs Anatase, 20.17 nm (XRD) and 1–25 nm (TEM) | Equivocal | 2/limited | Zirak et al. (2016) |
| MN assay in peripheral blood reticulocytes Mice 0.5, 5.0 and 50 mg/kg bw/day, for 3 days | NSC: 1, TiO2 NPs, Anatase, ellipsoidal shape (TEM), minor axes 12.1 ± 3.2 nm | Negative | 2/limited | Sadiq et al. (2012) |
| Intravenous injection | ||||
| MN test in bone marrow PCE and reticulocytes Rats 5 mg/kg bw Single administration | NSC: 2, TiO2 NPs (NM‐105), 15–24 nm | Positive | 2/limited | Dobrzynska et al. (2014) |
| MN in peripheral blood reticulocytes Transgenic mice 2–50 mg/kg bw per week for 4 consecutive weeks | NSC: 1, TiO2 NPs (P25) 15–24 nm | Negative | 2/limited | Suzuki et al. (2016) |
| MN test in peripheral blood reticulocytes Transgenic mice 10 and 15 mg/kg bw 2 days | NSC: 1, TiO2 NPs (NM‐102), 21–22 nm | Negative | 2/limited | Louro et al. (2014) |
NSC: nanoscale considerations, MN: micronucleus assay, CA: chromosomal aberration assay, XRD: X‐ray diffraction; TEM: transmission electron microscopy, PCE: polychromatic erythrocytes; bw: body weight.