Toxicogenomics study of nanomaterials on the model organism zebrafish

We have adapted an "in vitro" toxicity test using zebrafish embryos for a toxicogenomics approach. Our goal is to develop a rapid toxicity assay for nanoparticles to be used in food and other applications. We incubated fertilized fish eggs for 48 h in the presence of a solution of purified MWCNT (1 ppb to 10 ppm) or with nanosilver solutions (1 ppb to 5 ppm). We could not detect effects on development or timing. We have used quantitative RT-PCR to analyze the expression patterns of Cyp1A1, Ahr2, Cpt1, iNOS, Ncf1, NudT1, c/EBP-a and MafT. These genes are involved in detoxification patterns, in the protection against oxidative stress or code for regulatory factors involved in the immune response. At these concentrations, nanosilver had clear effects on the expression of most of the genes in a dose dependant manner. Induction was maximum in the case of regulatory factors. On the contrary, changes in gene expression induced by MWCNTs were much lower, suggesting a reduced toxicity at the tested concentrations.