Genotoxicity and Gene Expression in the Rat Lung Tissue following Instillation and Inhalation of Different Variants of Amorphous Silica Nanomaterials (aSiO2 NM)

Several reports on amorphous silica nanomaterial (aSiO2 NM) toxicity have been questioning their safety. Herein, we investigated the in vivo pulmonary of four variants aSiO2 NM: SiO2_15_Unmod, SiO2_15_Amino, SiO2_7 and SiO2_40. We focused alterations lung DNA protein integrity, gene expression following single intratracheal instillation rats. Additionally, a short-term inhalation study (STIS) was carried out for SiO2_7, using TiO2_NM105 as benchmark NM. In study, significant but slight increase oxidative damage rats exposed to highest instilled dose (0.36 mg/rat) SiO2_15_Amino observed recovery (R) group. Exposure or SiO2_40 markedly increased lesions rat cells exposure (E) group at every tested dose. This seems be repaired, since no changes compared controls were R groups. STIS, strand breaks 0.5 mg/m3 50 both The detected suggest that stress and/or inflammation pathways are likely implicated induction (oxidative) damage. Overall, all NM not associated with marked STIS. genotoxicity findings from STIS concordant; however, animals more permanent/difficult revert.