Engineered Nanomaterials: Knowledge Gaps in Fate, Exposure, Toxicity, and Future Directions

Table 2

Oral toxicity of TiO₂ to rats and in vitro data on rat cell lines.

Reference	Exposed animals/cell line type	Experimental design	Endpoint
Hussain et al. [111]	BRL 3A rat liver cell line	Exposure of TiO2 particles for 24 hours in  vitro to 40 nm TiO2 particles	Cytotoxicity; mitochondrial function
Trouiller et al. [13]	Rats	Exposure of TiO2 particles (21 nm size, 75% anatase, and 25% rutile) through drinking water	DNA single and double strand breakage; chromosomal damage in vivo; DNA deletions in offspring
Kocbek et al. [112]	HEK cells	Effect of TiO2 and ZnO particles on HEK cells in vitro	Cytotoxicity

ENM: engineered nanomaterial; HEK cells: human embryonic kidney cells; ROS: reactive oxygen species.