Table 1 Summary of recent in vivo experiments carried out with CNTs
From: Mesothelioma: Do asbestos and carbon nanotubes pose the same health risk?
Type of CNT | System | Summary results | Reference |
|---|---|---|---|
SWCNTs (Carbon nanotech Inc. Tx). Ø: 0.8–1.2 nm L: 0.1–1 μm | Pharyngeal deposition in C57Bl/6 mice lung (40 μg/mouse). Observation 4 hours post exposure. | Gene expression in lung and blood: Upregulation of genes involved in inflammation, oxidative stress, coagulation, tissue remodeling. Increased percentage of polymorphonuclear leucocytes (PMN) in blood and bronchoalveolar lavage (BAL). | [30] |
SWCNTs. 240 nm (mode, aerodynamic diameter; in number) | Inhalation (4 days) in mice – 5 mg/m3 Short and mean term responses (1, 7, 28 days) | Lung analysis: Inflammation – Granulomas – Fibrosis – Mutation of K-ras | [58] |
4.2 μm (mode, aerodynamic diameter; in mass) | Laryngeal deposition (10 μg/mouse). Short and mean term responses (1, 7, 28 days) | Lung analysis: Inflammation – Granulomas – Fibrosis - No mutation of K-ras. Lower effects compared to inhalation. | |
MWCNTs. Ø: 40–60 nm L:0.5–500 μm | Intratracheal deposition in rats. One to 7 mg/kg. Short/mean term responses (1 to 90 days) | Inflammation; dose-dependent thickening of the alveolar lining Particles still present after 3 months | [56] |
MWCNTs grinded, unheated, heated to 600°C, 2400°C; 2400°C then grinded. Ø: 20–50 nm L: 0.7 ± 0.07 μm | Intratracheal deposition in rats, 2 mg/rat. Short-term response (3 days); mean-term (60 days) | Inflammation (3 days). Granulomas (60 days). Effects of heated CNTs lower than unheated. Grinding restored the effects. | [57] |
MWCNTs. Ø: 40–60 nm L:0.5–500 μm | Intratracheal deposition in rats. One to 7 mg/kg. Short/mean term responses (1 to 90 days) | Inflammation; dose-dependent thickening of the alveolar lining Particles still present after 3 months | [56] |
MWCNTs (Mitsui & Co., LDT) Ø: ≅ 80 nm L: 10–20 μm | Pharyngeal deposition in C57Bl/6 mice lung (40 μg/mouse). Observation 4 hours post exposure. | Gene expression in lung and blood: Upregulation of genes involved in inflammation, oxidative stress, coagulation, tissue remodeling. Increased percentage of polymorphonuclear leucocytes (PMN) in blood and bronchoalveolar lavage (BAL). | [30] |
MWCNTs Shenzhen nanotech Ø: 500 nm; L: 10 μm | Inhalation (≈ 32 mg/m3) in mice for 5, 10, 15 days; deposition ≈ 0.07, 0.14; 0.24 μg/mouse. Short-term response (8, 16, 24 days) | Small aggregates entering the alveolar wall Cell proliferation and thickening of alveolar walls | [59] |
Tracheal deposition: 50 μg/mouse | Eight and 16 days: clumps deposited on lining wall of bronchi, no inflammation – 24 days: inflammation. Clumps in the alveoli destruction of alveolar structure |