The interactions of fullerene C60 and Benzo(α)pyrene influence their bioavailability and toxicity to zebrafish embryos

This study aimed to assess the toxicological consequences related to the interaction of fullerene nanoparticles (C60) and Benzo(α)pyrene (B(α)P) on zebrafish embryos, which were exposed to C60and B(α)P alone and to C60doped with B(α)P. The uptake of pollutants into their tissues and intra-cellular localization were investigated by immunofluorescence and electron microscopy. A set of biomarkers of genotoxicity and oxidative stress, as well as functional proteomics analysis were applied to assess the toxic effects due to C60interaction with B(α)P. The carrier role of C60for B(α)P was observed, however adsorption on C60did not affect the accumulation and localization of B(α)P in the embryos. Instead, C60doped with B(α)P resulted more prone to sedimentation and less bioavailable for the embryos compared to C60alone. As for toxicity, our results suggested that C60alone elicited oxidative stress in embryos and a down-regulation of proteins involved in energetic metabolism. The C60+ B(α)P induced cellular response mechanisms similar to B(α)P alone, but generating greater cellular damages in the exposed embryos. Once C60nanoparticles and B(α)P meet in water, they reciprocally affect their bioavailability and, by consequence, their toxicity to organisms.