Single-Dosed Genotoxicity Study of Gold Nanorod Core/Silver Shell Nanostructures by Pig-a , Micronucleus, and Comet Assays.

As an increasing number of nanoproducts enter our daily life, their potential health risks have caused widespread concerns and have also promoted studies of nanotoxicity. Among these investigations, the genotoxicity of nanomaterials has attracted more attention. Engineered silver nanorod with gold core and silver shell (Au@Ag NR) was used in this study to investigate the possible genotoxicity and genotoxicity patterns in peripheral lymphocytes and hepatocytes introduced by released Ag+ and the nanoparticle itself by integrating the Pig-a gene, micronucleus, and comet assays. Most of the Au@Ag NR was rapidly cleared from the circulatory system of Sprague Dawley rats, and a small amount of Au@Ag NR was retained in the liver for at least 14 days. Our data confirmed that clastogenicity was the primary genotoxicity type induced by Au@Ag NR, and both NR particles containing Ag and the released Ag+ contribute to genotoxicity. Au@Ag NR was shown to be a clastogen through the introduction of increased %Tail DNA in peripheral lymphocytes (5.82%±0.25%) and hepatocytes (4.83%±0.17%) and promotion of the formation of micronuclei in hepatocytes (1.12%±0.13%) 3 days and 14 days after dosing, respectively (P < 0.05), which could be a result of both Ag+ and Ag shell of the Au@Ag NR. However, Au@Ag NR was not shown to be a mutagen, as the average RBCCD59- count was not changed significantly as compared with control. These data suggest the importance of adopting appropriate genotoxicity testing strategies in identifying the genotoxicity of nanoparticles in vivo.