title: Interactions of multiwalled carbon nanotubes with algal cells: quantification of association, visualization of uptake, and measurement of alterations in the composition of cells.
abstract: Carbon nanotubes (CNTs) are considered promising materials in nanotechnology. We quantified CNT accumulation by the alga Desmodesmus subspicatus. Cells were exposed to radiolabeled CNTs ((14)C-CNTs;1 mg/L) to determine uptake and association, as well as elimination and dissociation in clear media.Attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) was used to detect effects of CNTs on algae. CNT-cell interactions were visualized by electron microscopy and related to alterations in their cell composition. A concentration factor of 5000 L/kg dry weight was calculated. Most of the material agglomerated around the cells, but single tubes were detected in the cytoplasm. Computational analyses of the ATR-FTIR data showed that CNT treated algae differed from controls at all sampling times.CNT exposure changed the biochemical composition of cells. The fact that CNTs are bioavailable for algae and that they influence the cell composition is important with regard to environmental risk assessment of this nanomaterial.
authors.affiliation: Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany. stefan.rhiem@bio5.rwth-aachen.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Rhiem
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Riding
authors.forename: Werner
authors.initials: W
authors.lastname: Baumgartner
authors.forename: Francis L
authors.initials: FL
authors.lastname: Martin
authors.forename: Kirk T
authors.initials: KT
authors.lastname: Semple
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Jones
authors.forename: Andreas
authors.initials: A
authors.lastname: Schäffer
authors.forename: Hanna M
authors.initials: HM
authors.lastname: Maes
mesh_terms: D000460:Chlorophyta / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D037742:Nanotubes, Carbon / Q000032:analysis / Q000737:chemistry* / Q000633:toxicity; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity
chemical_list: D037742:Nanotubes, Carbon; D014874:Water Pollutants, Chemical