Table 1 Bio-distribution of TiO₂ NPs after rat/mice were administrated by different routes

Both anatase and rutile forms (70/30)

Male Wistar rats

Intravenous injection

20–30 nm; no surface coating; 5 mg/kg body weight (BW); single injection

Liver, spleen, lung, and kidney detected; blood cells, plasma, lymph nodes, and brain not detected

[73]

Both anatase and rutile forms (80/20)

BALB/c female mice

Subcutaneous (s.c.) injection

Hydrodynamic diameters ranging from 114 to 122 nm; 5600 mg/kg BW; 2 consecutive days

Liver, lymph node and spleen detected; brain not detected

[74]

Intravenous (i.v.) injection

Hydrodynamic diameters ranging from 114 to 122 nm; 560 mg/kg BW; 2 consecutive days

Lung, liver, lymph node, spleen and kidney detected; brain not detected

Rutile

Male mice

Intravenous injection

Primary particle diameter 15 nm, secondary particle size 120 nm; 1813 μg/animal

Liver, kidney, blood detected; brain not detected

[75]

Rutile

CD-1 (ICR) female mice

Intranasal instillation

80 nm; 50 mg/kg BW; every other day for 30 days

Lung and brain detected; liver, heart, and spleen not detected

[16]

Anatase

155 nm; 50 mg/kg BW; every other day for 30 days

Degussa P25

Rats

Intravenous administration

21 nm; spherical; 0.95 mg/kg BW; single injection

Liver (highest), spleen, lung, kidney, heart and blood detected; brain not detected

[113]

Anatase 80: 20 rutile

Sprague–Dawley rats

Oral administration

21 nm; spherical; 260.4, 520.8, and 1041.5 mg/kg/day BW; every day for 13 weeks (7 days/week)

Low absorption in other organs and brain not detected

[78]

Anatase

Male Kunming mice

Inhalation exposure

20 nm; steady concentration (6.34 ± 0.22 mg m⁻³); 8 h per day for 3 weeks

Lungs, liver, blood, and urine detected; kidney and brain not detected

[114]