title: Multi-walled carbon nanotube induced frustrated phagocytosis, cytotoxicity and pro-inflammatory conditions in macrophages are length dependent and greater than that of asbestos.
abstract: The potential toxicity of carbon nanotubes (CNTs) has been compared to pathogenic fibres such as asbestos. It is important to test this hypothesis to ascertain safe methods for CNT production, handling and disposal. In this study aspects reported to contribute to CNT toxicity were assessed: length, aspect ratio, iron content and crystallinity; with responses compared to industrially produced MWCNTs and toxicologically relevant materials such as asbestos. The impacts of these particles on a range of macrophage models in vitro were assessed due to the key role of macrophages in particle clearance and particle/fibre-induced disease. Industrially produced and long MWCNTs were cytotoxic to cells, and were potent in inducing pro-inflammatory and pro-fibrotic immune responses. Short CNTs did not induce any cytotoxicity. Frustrated phagocytosis was most evident in response to long CNTs, as was respiratory burst and reduction in phagocytic ability. Short CNTs, metal content and crystallinity had less or no influence on these endpoints, suggesting that many responses were fibre-length dependent. This study demonstrates that CNTs are potentially pathogenic, as they were routinely found to induce detrimental responses in macrophages greater than those induced by asbestos at the same mass-based dose.
authors.affiliation: Centre for Nano Safety, Edinburgh Napier University, UK. Electronic address: matboyles@yahoo.co.uk.
authors.forename: Matthew S P
authors.initials: MS
authors.lastname: Boyles
authors.affiliation: Centre for Nano Safety, Edinburgh Napier University, UK.
authors.forename: Lesley
authors.initials: L
authors.lastname: Young
authors.affiliation: Centre for Nano Safety, Edinburgh Napier University, UK; Heriot-Watt University, School of Life Sciences, UK.
authors.forename: David M
authors.initials: DM
authors.lastname: Brown
authors.affiliation: Institute of Occupational Medicine, UK.
authors.forename: Laura
authors.initials: L
authors.lastname: MacCalman
authors.affiliation: Institute of Occupational Medicine, UK.
authors.forename: Hilary
authors.initials: H
authors.lastname: Cowie
authors.affiliation: Department of Materials Science and Metallurgy, University of Cambridge, UK.
authors.forename: Anna
authors.initials: A
authors.lastname: Moisala
authors.affiliation: Department of Materials Science and Metallurgy, University of Cambridge, UK.
authors.forename: Fiona
authors.initials: F
authors.lastname: Smail
authors.affiliation: Centre for Nano Safety, Edinburgh Napier University, UK.
authors.forename: Paula J W
authors.initials: PJ
authors.lastname: Smith
authors.affiliation: Centre for Nano Safety, Edinburgh Napier University, UK.
authors.forename: Lorna
authors.initials: L
authors.lastname: Proudfoot
authors.affiliation: Department of Materials Science and Metallurgy, University of Cambridge, UK.
authors.forename: Alan H
authors.initials: AH
authors.lastname: Windle
authors.affiliation: Centre for Nano Safety, Edinburgh Napier University, UK; Heriot-Watt University, School of Life Sciences, UK.
authors.forename: Vicki
authors.initials: V
authors.lastname: Stone
mesh_terms: D000818:Animals; D017639:Asbestos, Amosite / Q000633:toxicity; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000378:metabolism; D006801:Humans; D007501:Iron / Q000032:analysis; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D008297:Male; D051379:Mice; D037742:Nanotubes, Carbon / Q000737:chemistry / Q000633:toxicity*; D010316:Particle Size; D010587:Phagocytosis / Q000187:drug effects; D017207:Rats, Sprague-Dawley; D053260:Soot / Q000633:toxicity; D053773:Transforming Growth Factor beta1 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D018932:Chemokine CCL2; D037742:Nanotubes, Carbon; D053260:Soot; D053773:Transforming Growth Factor beta1; D014409:Tumor Necrosis Factor-alpha; D017639:Asbestos, Amosite; D007501:Iron
keywords: Asbestos; Carbon nanotubes; Frustrated phagocytosis; Nanoparticles