Accumulation of Silver Nanoparticles in Brain and Testes during Long-Term Ingestion to Mammals

Using of silver nanoparticles in consumer goods and in medicine gives big benefits, but there is also the problem of their toxicity for health and environment. There is a lot of literature on experiments with absorption, biodistribution, metabolism and excretion (ADME) of silver nanoparticles in living organisms, but low information exists yet on their accumulation in various biological organs of mammals. Previous experiments have indicated a low clearance of silver nanoparticles from organs, which have histochematic barriers, e.g brain, testes. This article reports the results of three month experiment with daily ingestion of silver nanoparticles to growing male Wistar rats. Experiment was aimed to measure silver mass accumulated in rat's brain and testes under various daily doses. The experiment shows that these organs accumulate silver nanoparticles. Сoncentration of silver nanoparticles in brain and testes after three month of daily ingestion shows dozens times increase compared to single ingestion of daily dose. The experiment demonstrates that accumulation of silver nanoparticles in brain and testes depends on value of daily dose of the nanoparticles. This dependence in brain differs from the same dependence in testes which demonstrate effect of “saturation” or less accumulation with increasing of daily dose. The results of the experiment are of great importance for estimation of toxicity of silver nanoparticles for mammals, developing of regulation documents on using of Ag NPs and for targeted transportation of pharmaceutical drugs.