Augmentation of lipid peroxidation and tissue injuries in rats exposed by sub-acute inhalation to nano-silver particles containing tween-20

Nanosilver particles (NSPs) used by customers may contain detergents/solvents. However, in most of the toxicological studies, nanosilvers are prepared in water and very little is known about the interaction of these agents with NSPs in causing adverse effects. The aim of this study was to investigate the interaction of NSPs and tween-20 in causing tissue injuries after inhalation. In this experiment, 16 rats were divided into four groups (n=4/group) as follows. Controls, exposed to water vapors; Tween-treated exposed to tween-20 alone (0.01% V/V); NSP-tween group exposed to 1000 ppm containing tween-20; Group treated with 1000 ppm of NSP alone. Whole-body exposure technique was performed in an exposure chamber for 16 hours (4 hours/day for 4 days). At the end of exposure, blood, liver and lungs were collected and processed for histopathological analysis. Serum glucose, total protein, alkaline phosphatase (ALP), aspartate transaminase (AST) and lactate dehydrogenase (LDH) were compared between experimental groups. The results showed no significant changes in serum ALT, AST, glucose, and albumin in rats exposed to either NSP or NSP suspended in tween-20. Whereas, lipid peroxidation in liver and lungs in rats exposed to NSPs prepared in tween-20 was elevated by 50 and 95% respectively compared to their controls (p<0.05). The interaction of tween-20 and Ag-NSP was further confirmed by observing tissue damage (histology) in tissues. In conclusion, data show that exposure to NSPs prepared in water is associated with negligible toxicity in rats. However, the toxicity of NSPs is potentiated if prepared in tween-20. It appears that Tween-20 can increase the absorption of NSPs and enhance lipid peroxidation in cellular and subcellular membranes leading to liver damage.