Nanoparticles modify embryonic genes expression in Xenopus laevis

Nanoparticles (NPs) exposure is inevitable as they are increasingly used in different areas. In medicine they assist the diagnosis of diseases. Their versatility is used for drug delivery system. The food industry also widely uses nanotechnology. NPs can penetrate into cells and interfere with their activity. They can also accumulate in organisms and in the food chain. Despite the rapid development of nanotechnology, informations on the exposure of organisms and environment to NPs is still limited and its implications have not been sufficiently explained. Therefore it is important to assess the risks associated with nanotechnology in order to identify potential damage. Exposure of organisms to the nanoparticulate is potentially hazardous, particularly when it occur during embryogenesis. Here we studied the effects of some nanoparticles (AgNPs, AuNPs, SiO2NPs; MKnano, Canada) on the embryogenesis of Xenopus laevis, a model for these kind of studies. The possibility of relating the data obtained in Xenopus with higher vertebrates, including humans, makes it a convincing study model. These NPs have been used to understand the possible consequences of similar NPs utilized in medicine or food. The embryos were reared from st. 2/4 in FETAX containing 0.01, 1 and 5 mg/L of NPs and harvested at stage 46/48. As control, sibling embryos were used. Our data show that all NPs aggregate into FETAX (DLS data) and do not cause mortality but affect embryonic development. To explain the origin of the embryonic problems we verify the ROS production and the expression of some genes involved in early embryogenesis (fgf8, bmp4, sox9, pax6, egr2, rax1). We have shown that these NPs stimulate increased of ROS production and changes in gene expression depending on the NPs concentration.