Investigations on the Accumulation, Tissue Distribution and Toxicity of Silver Nanoparticles in Amammalian Model

Abstract

The current work aimed to investigate the potential toxicity of Ag-NPs in male rabbits as a mammalian model, following acute and sub-acute dermal exposure terms. The rabbits were topically exposed to a single acute dose of 2.0% Ag-NPs and the assessments were conducted4 days latter, while a dose of 0.5% was administered every other day for the sub-acute exposure in two time periods (7 and 14 days). The accumulation and retention of Ag+ ions in the skin and their distribution in other vital tissues were measured. In addition, the concentrations of total proteins, lipidparameters and levels of different oxidative stress biomarkers in the skin were also evaluated. The results demonstrated the ability of Ag-NPs to penetrate the skin and accumulate rapidly in the dermal skin, then spread out to the blood and other vital organs. The spleen and liver seemed to be the main target organs. The high levels of Ag+ tissue accumulation affected the concentration of total proteins and acted as a stressor stimulus within the skin, thereby, initiating oxidative stress. The liberated ROS caused disruption of the activities of the antioxidant enzymes GST, GSH, GR, GPx, SOD and CAT as well as increased levels of H2O2 and MDA. The current work showed that the toxicity of Ag-NPs could be attributed to the release of Ag+ ions and the subsequent excessive generation of ROS.