The recent widespread applications of nanomaterials, because of their properties, opens new scenarios that affect their dispersal in the environment. In particular multiwall carbon nanotubes (MWCNTs), despite their qualities, seem to be harmful for animals and humans. To evaluate possible toxic effects caused by carbon nanotube environmental dispersion, with regard to aquatic compartment, we proposed as experimental model a freshwater invertebrate: Hirudo medicinalis. In the present study we analyse acute and chronic immune responses over a short (1, 3, 6 and 12 hours) and long time (from 1 to 5 weeks) exposure to MWCNTs by optical, electron and immunohistochemical approaches. In the exposed leeches angiogenesis and fibroplasia accompanied by massive cellular migration occur. Immunocytochemical characterization using specific markers shows that in these inflammatory processes the monocyte-macrophages (CD45+, CD68+) are the most involved cells. These immunocompetent cells are characterized by sequence of events starting from the expression of pro-inflammatory cytokines (in particular IL-18), and amyloidogenensis. Our combined experimental approaches, basing on high sensitive inflammatory response can highlight adverse effects of nanomaterials on aquatic organisms and could be useful to assess the MWCNTs impact on aquatic, terrestrial animal and human health.

This study aimed to assess the toxicological consequences related to the interaction of fullerene nanoparticles (C) and Benzo(α)pyrene (B(α)P) on zebrafish embryos, which were exposed to C and B(α)P alone and to C doped 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 C interaction with B(α)P. The carrier role of C for B(α)P was observed, however adsorption on C did not affect the accumulation and localization of B(α)P in the embryos. Instead, C doped with B(α)P resulted more prone to sedimentation and less bioavailable for the embryos compared to C alone. As for toxicity, our results suggested that C alone elicited oxidative stress in embryos and a down-regulation of proteins involved in energetic metabolism. The C + B(α)P induced cellular response mechanisms similar to B(α)P alone, but generating greater cellular damages in the exposed embryos.

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