title: Uptake of noncytotoxic acid-treated single-walled carbon nanotubes into the cytoplasm of human macrophage cells.
abstract: Water-soluble single-walled nanotubes (SWNTs) are being tested as contrast agents for medical imaging and for the delivery of therapeutically active molecules to target cells. However, before they become used commercially, it will be essential to establish their subcellular distribution and whether they are cytotoxic. Here we characterize uptake of unlabeled, acid-treated, water-soluble SWNTs by human monocyte derived macrophage cells using a combination of Raman spectroscopy and analytical electron microscopy and compare our findings to previous work on unpurified SWNTs. Raman spectroscopy demonstrated that acid-treated SWNTs had a greater number of functional groups on the carbon walls than nontreated SWNT. The acid-treated SWNTs were less aggregated within cells than unpurified SWNTs. Bundles, and also individual acid-treated SWNTs, were found frequently inside lysosomes and also the cytoplasm, where they caused no significant changes in cell viability or structure even after 4 days of exposure.
authors.affiliation: Department of Materials, Imperial College London, South Kensington, London, United Kingdom. a.porter@imperial.ac.uk
authors.forename: Alexandra E
authors.initials: AE
authors.lastname: Porter
authors.forename: Mhairi
authors.initials: M
authors.lastname: Gass
authors.forename: James S
authors.initials: JS
authors.lastname: Bendall
authors.forename: Karin
authors.initials: K
authors.lastname: Muller
authors.forename: Angela
authors.initials: A
authors.lastname: Goode
authors.forename: Jeremy N
authors.initials: JN
authors.lastname: Skepper
authors.forename: Paul A
authors.initials: PA
authors.lastname: Midgley
authors.forename: Mark
authors.initials: M
authors.lastname: Welland
mesh_terms: D003593:Cytoplasm / Q000378:metabolism*; D006801:Humans; D008264:Macrophages / Q000378:metabolism*; D017348:Microscopy, Electron, Scanning Transmission; D037742:Nanotubes, Carbon; D013059:Spectrum Analysis, Raman
chemical_list: D037742:Nanotubes, Carbon