title: Synergistic mitotoxicity of chloromethanes and fullerene C60nanoaggregates in Daphnia magna midgut epithelial cells.
abstract: Adsorption of non-polar compounds by suspended fullerene nanoaggregates (nC60) may enhance their toxicity and affect the fate, transformation, and transport of non-polar compounds in the environment. The potential of stable fullerene nanoaggregates as contaminant carriers in aqueous systems and the influence of chloromethanes (trichloromethane and dichloromethane) were studied on the midgut epithelial cells of Daphnia magna by light and electron microscopy. The size and shape of fullerene nanoaggregates were observed and measured using dynamic light scattering, transmission electron microscopy, and low vacuum scanning electron microscopy. The nC60in suspension appeared as a bulk of aggregates of irregular shape with a surface consisting of small clumps 20-30 nm in diameter. The presence of nC60aggregates was confirmed in midgut lumen and epithelial cells of D. magna. After in vivo acute exposure to chloromethane, light and electron microscopy revealed an extensive cytoplasmic vacuolization with disruption and loss of specific structures of D. magna midgut epithelium (mitochondria, endoplasmic reticulum, microvilli, peritrophic membrane) and increased appearance of necrotic cells. The degree of observed changes depended on the type of treatment: trichloromethane (TCM) induced the most notable changes, whereas fullerene nanoaggregates alone had no negative effects. Transmission electron microscopy also indicated increased lysosomal degradation and severe peroxidative damages of enterocyte mitochondria following combined exposure to chloromethane and fullerene nanoaggregates. In conclusion, the adsorption of chloromethane by fullerene nanoaggregates enhances their toxicity and induces peroxidative mitochondrial damage in midgut enterocytes.
authors.affiliation: University of Belgrade, Institute of Nuclear Sciences "Vinca", Laboratory for Radiobiology and Molecular Genetics, Belgrade, Republic of Serbia.
authors.forename: Mariana
authors.initials: M
authors.lastname: Seke
authors.affiliation: University of Belgrade, Faculty of Biology, Centre for Electron Microscopy, Belgrade, Republic of Serbia.
authors.forename: Milica
authors.initials: M
authors.lastname: Markelic
authors.affiliation: University of Belgrade, Faculty of Biology, Belgrade, Republic of Serbia.
authors.forename: Arian
authors.initials: A
authors.lastname: Morina
authors.affiliation: University of Novi Sad, Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, Novi Sad, Republic of Serbia.
authors.forename: Danica
authors.initials: D
authors.lastname: Jovic
authors.affiliation: University of Belgrade, Faculty of Biology, Centre for Electron Microscopy, Belgrade, Republic of Serbia.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Korac
authors.affiliation: University of Belgrade, Faculty of Biology, Belgrade, Republic of Serbia. draganam@bio.bg.ac.rs.
authors.forename: Dragana
authors.identifier: http://orcid.org/0000-0002-6034-5145
authors.initials: D
authors.lastname: Milicic
authors.affiliation: University of Novi Sad, Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, Novi Sad, Republic of Serbia.
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Djordjevic
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002725:Chloroform / Q000633:toxicity*; D003621:Daphnia; D004357:Drug Synergism; D004847:Epithelial Cells / Q000187:drug effects / Q000648:ultrastructure; D037741:Fullerenes / Q000633:toxicity*; D041981:Gastrointestinal Tract / Q000166:cytology; D008752:Methylene Chloride / Q000633:toxicity*; D008928:Mitochondria / Q000187:drug effects* / Q000648:ultrastructure; D053758:Nanoparticles / Q000633:toxicity / Q000648:ultrastructure; D010316:Particle Size; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D037741:Fullerenes; D014874:Water Pollutants, Chemical; D008752:Methylene Chloride; D002725:Chloroform
keywords: Cellular damage; Choromethanes; Daphnia magna; Electron microscopy; Fullerenes; Lipid peroxidation