The accumulation and tissue distribution of gold nanoparticles in exposed pregnant rats†

Abstract

The limited research on the toxicokinetics of nanoparticles (NPs) in pregnant rats hinders our understanding of the potential risks they pose to the pregnant population. Thus, in this study, we examined how the dose and size of NPs impact their specific distribution in exposed pregnant rats under repeated dosing. Results revealed that Au NPs mainly accumulated in the spleen and liver, followed by the uterus, while the heart, placenta, and fetus showed the least accumulation. A decrease in the exposure size of the Au NPs induced their faster elimination from serum and organs. An increase in the exposure dose induced faster elimination from serum but slower elimination from organs, higher accumulation, and increased particle size of Au NPs in vivo. The accumulation and biodistribution of the Au NPs varied across different organs depending on their size. Particularly, Au NPs with an in vivo size of 40 nm were shown to cross the placenta and accumulate in the fetus, regardless of their exposure dose and size. This effect was closely related to the transport routes of the Au NPs across the placenta, possibly via vesicular transport and uptake by trophoblast cells. Our study illustrating the specific distribution of NPs in vivo provides important evidence for assessing their health risks.