A comparison of acute and long-term effects of industrial multiwalled carbon nanotubes on human lung and immune cells in vitro.
The close resemblance of carbon nanotubes to asbestos fibers regarding their high aspect ratio, biopersistence and reactivity increases public concerns on the widespread use of these materials. The purpose of this study was not only to address the acute adverse effects of industrially produced multiwalled carbon nanotubes (MWCNTs) on human lung and immune cells in vitro but also to further understand if their accumulation and biopersistence leads to long-term consequences or induces adaptive changes in these cells. In contrast to asbestos fibers, pristine MWCNTs did not induce overt cell death in A549 lung epithelial cells and Jurkat T lymphocytes after acute exposure to high doses of this material (up to 30 μg/ml). Nevertheless, very high levels of reactive oxygen species (ROS) and decreased metabolic activity were observed which might affect long-term viability of these cells. However, the continuous presence of low amounts of MWCNTs (0.5 μg/ml) for 6 months did not have major adverse long-term effects although large amounts of nanotubes accumulated at least in A549 cells. Moreover, MWCNTs did not appear to induce adaptive mechanisms against particle stress in long-term treated A549 cells. Our study demonstrates that despite the high potential for ROS formation, pristine MWCNTs can accumulate and persist within cells without having major long-term consequences or inducing adaptive mechanisms.
Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Materials-Biology Interactions, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland. tina.thurnherr@empa.ch
Tina
T
Thurnherr
Christina
C
Brandenberger
Kathrin
K
Fischer
Liliane
L
Diener
Pius
P
Manser
Xenia
X
Maeder-Althaus
Jean-Pierre
JP
Kaiser
Harald F
HF
Krug
Barbara
B
Rothen-Rutishauser
Peter
P
Wick
D017209:Apoptosis / Q000187:drug effects; D001194:Asbestos / Q000633:toxicity; D016923:Cell Death / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D020552:Comet Assay; D004305:Dose-Response Relationship, Drug; D004705:Endocytosis / Q000187:drug effects; D004847:Epithelial Cells / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D019169:Jurkat Cells; D008168:Lung / Q000166:cytology / Q000187:drug effects*; D015162:Micronucleus Tests; D046529:Microscopy, Electron, Transmission; D037742:Nanotubes, Carbon / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D013778:Tetrazolium Salts; D013844:Thiazoles
D037742:Nanotubes, Carbon; D017382:Reactive Oxygen Species; D013778:Tetrazolium Salts; D013844:Thiazoles; D001194:Asbestos; C022616:thiazolyl blue