title: Characterisation and in vivo ecotoxicity evaluation of double-wall carbon nanotubes in larvae of the amphibian Xenopus laevis.
abstract: Because of their outstanding properties, carbon nanotubes (CNTs) are being assessed for inclusion in many manufactured products. Due to their massive production and growing number of potential applications, the impact of CNTs on the environment must be taken into consideration. The present investigation evaluates the ecotoxicological potential of double-walled carbon nanotubes (DWNTs) in the amphibian larvae Xenopus laevis at a large range of concentrations in water (from 10 to 500 mgL(-1)). Acute toxicity and genotoxicity were analysed after 12 days of static exposure in laboratory conditions. Acute toxicity was evaluated according to the mortality and the growth of larvae. The genotoxic effects were analysed by scoring the micronucleated erythrocytes of the circulating blood of larvae according to the International Standard micronucleus assay. Moreover, histological preparations of larval intestine were prepared after 12 days of exposure for observation using optical and transmission electron microscopy (TEM). Finally, the intestine of an exposed larva was prepared on a slide for analyse by Raman imaging. The results showed no genotoxicity in erythrocytes of larvae exposed to DWNTs in water, but acute toxicity at every concentration of DWNTs studied which was related to physical blockage of the gills and/or digestive tract. Indeed, black masses suggesting the presence of CNTs were observed inside the intestine using optical microscopy and TEM, and confirmed by Raman spectroscopy analysis. Assessing the risks of CNTs requires better understanding, especially including mechanistic and environmental investigations.
authors.affiliation: Laboratoire d'Ecologie fonctionnelle - EcoLab, Université Paul Sabatier, UMR UPS INPT CNRS 5245, Campus INP-ENSAT, Avenue de l'Agrobiopole, 31326 Auzeville-Tolosane, France. florence.mouchet@cict.fr
authors.forename: Florence
authors.initials: F
authors.lastname: Mouchet
authors.forename: Perine
authors.initials: P
authors.lastname: Landois
authors.forename: Elodie
authors.initials: E
authors.lastname: Sarremejean
authors.forename: Guillaume
authors.initials: G
authors.lastname: Bernard
authors.forename: Pascal
authors.initials: P
authors.lastname: Puech
authors.forename: Eric
authors.initials: E
authors.lastname: Pinelli
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Flahaut
authors.forename: Laury
authors.initials: L
authors.lastname: Gauthier
mesh_terms: D000818:Animals; D007814:Larva / Q000187:drug effects; D046529:Microscopy, Electron, Transmission; D009152:Mutagenicity Tests; D037742:Nanotubes, Carbon / Q000633:toxicity*; D013059:Spectrum Analysis, Raman; D023382:Toxicity Tests, Acute; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D014982:Xenopus laevis / Q000254:growth & development / Q000502:physiology*
chemical_list: D037742:Nanotubes, Carbon; D014874:Water Pollutants, Chemical