Toxicopathological examinations after repeated intraperitoneal administration of silver nanoparticles in the Wistar rat model

Objective(s): Due to wide range of medical applications as bactericidal agents, nanosilver particles (NSPs) are manufactured worldwide in large quantities. However, potential toxicity impacts of NSPs in humans and animals still remain poorly understood. The objective of this study was to investigate clinical observations, mortality and pathological changes in rats following intraperitoneal administration of different doses of NSPs. Methods: In this study, rats were administered intraperitoneally over a period of 5 days with repeated doses at different dose levels (20, 80, 320 mg/kg) of NSPs (20 nm). Rats were euthanized 14 days after the treatment. Animal mortality, clinical sings, food intake and body weight were evaluated. Histopathology was performed on heart, lung, liver and kidneys of experimented animals. Results: There was a significant decrease in the body weight of animals in high dose group following fourteen days of exposure. Also, there was significant decrease in food intake during the treatment period in high dose group. Histological tissue sections indicated that NSPs induced multi-organ pathological lesions including severe alveolar edema, hemorrhage and inflammation in lungs, myocytolysis, congestion and edema in heart, inflammation and congestion in kidney and liver. Conclusions: The results obtained two weeks following intraperitoneal injection indicate that the administration of high doses of NSPs could induce histopathological complications in heart, lung, liver and kidneys in rats. No significant pathological effects were observed in low and intermediate doses. More toxicological investigations are needed in relation of the application of NSPs with their potential threat as a medical tool.