Cytotoxicity of single-wall carbon nanotubes on human fibroblasts.
We present a toxicological assessment of five carbon nanomaterials on human fibroblast cells in vitro. We correlate the physico-chemical characteristics of these nanomaterials to their toxic effect per se, i.e. excluding catalytic transition metals. Cell survival and attachment assays were evaluated with different concentrations of refined: (i) single-wall carbon nanotubes (SWCNTs), (ii) active carbon, (iii) carbon black, (iv) multi-wall carbon nanotubes, and (v) carbon graphite. The refined nanomaterial that introduced the strongest toxic effect was subsequently compared to its unrefined version. We therefore covered a wide range of variables, such as: physical dimensions, surface areas, dosages, aspect ratios and surface chemistry. Our results are twofold. Firstly, we found that surface area is the variable that best predicts the potential toxicity of these refined carbon nanomaterials, in which SWCNTs induced the strongest cellular apoptosis/necrosis. Secondly, we found that refined SWCNTs are more toxic than its unrefined counterpart. For comparable small surface areas, dispersed carbon nanomaterials due to a change in surface chemistry, are seen to pose morphological changes and cell detachment, and thereupon apoptosis/necrosis. Finally, we propose a mechanism of action that elucidates the higher toxicity of dispersed, hydrophobic nanomaterials of small surface area.
Tian
Furong
F
Max Planck Institute for Metals Research, Heisenbergstrasse 3, 70569 Stuttgart, Germany. furong@mf.mpg.de
Cui
Daxiang
D
Schwarz
Heinz
H
Estrada
Giovani Gomez
GG
Kobayashi
Hisatashi
H
D000199:Actins / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D015820:Cadherins / Q000378:metabolism; D002244:Carbon / Q000737:chemistry / Q000494:pharmacology*; D002448:Cell Adhesion / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002606:Charcoal / Q000737:chemistry / Q000494:pharmacology; D024141:Collagen Type IV / Q000378:metabolism; D056743:Cyclin D3; D016213:Cyclins / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D051417:Focal Adhesion Kinase 1 / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007797:Laminin / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D013997:Time Factors
D000199:Actins; C534696:CCND3 protein, human; D015820:Cadherins; D024141:Collagen Type IV; D056743:Cyclin D3; D016213:Cyclins; D005353:Fibronectins; D007797:Laminin; D037742:Nanotubes, Carbon; D002606:Charcoal; D002244:Carbon; D051417:Focal Adhesion Kinase 1; C496050:PTK2 protein, human