Acute and Subacute Pulmonary Toxicity of Low Dose of Ultrafine Colloidal Silica Particles in Mice after Intratracheal Instillation

Abstract

To study the acute and subacute lung toxicity of low dose of ultrafine colloidal silica particles (UFCSs), mice were intratracheally instilled with 0, 0.3, 3, 10, 30 or 100 μg of UFCSs. Cellular and biochemical parameters in bronchoalveolar lavage fluid (BALF), histological alteration and the body weight were determined at 3 days after instillation. Exposure to 30 or 100 μg of UFCSs produced moderate to severe pulmonary inflammation and tissue injury. To investigate the time response, mice were instilled with 30 μg of UFCSs and sacrificed at intervals from 1 to 30 days postexposure. UFCSs induced moderate pulmonary inflammation and injury on BALF indices at acute period; however, these changes gradually regressed until recovery during the experiment. Concomitant histopathological and laminin immunohistochemical findings generally correlated to BALF data. TUNEL analyses in UFCSs-treated animals showed a significant increase of the apoptotic index in lung parenchyma at all observation times. 8-OHdG expression occurred in lung epithelial cells and activated macrophages, which correlated to lung lesions in UFCSs-treated mice. These findings suggest that instillation of a small dose of UFCSs causes transient acute moderate lung inflammation and tissue damage. Oxidative stress and apoptosis may underlie the lung tissue injury induction.

The role of oxidative stress in ambient particulate matter-induced lung diseases and its implications in the toxicity of engineered nanoparticles

“…While UFCS induced moderate lung inflammation during the acute phase, a significant increase in the apoptotic index could be seen in the lung parenchyma at all times. These lesions correlate with the induction of 8-hydroxyguanosine (8-OHdG) as an oxidative stress marker in lung epithelial cells and activated macrophages [122]. Subacute exposure of C57B1/6 mice to 2-5 nm TiO 2 NPs in a whole-body exposure chamber caused a moderate but significant inflammatory response in the lung within the first two weeks of exposure, beyond which the inflammation resolved without permanent damage [123].…”

Toxicity assessment on haemotology, biochemical and histopathological alterations of silver nanoparticles-exposed freshwater fish Labeo rohita

“…Furthermore, nanoparticles are also shown to cause toxicity by increasing concentration of intracellular ROS and decrease in antioxidant level (Singh et al 2009;Hussain et al 2009). The increase in ROS level is also an important indication of predominant mechanism of acute toxicity (Kaewamatawong et al 2006). In this study, synthesized AgNPs were assessed to explore the acute toxicity effects using Labeo rohita as an in vivo model.…”

Tissue distribution and excretion kinetics of orally administered silica nanoparticles in rats

“…lee et al acute and repeat dose toxicities, and biokinetics, [11][12][13][14][15][16][17][18][19] which are currently hot issues in the nanotoxicology field. However, the kinetic behaviors of silica nanoparticles at the systemic level, including their pharmacokinetics, tissue distributions, and clearances, remain unclear.…”