title: Physicochemical determinants of multiwalled carbon nanotubes on cellular toxicity: influence of a synthetic method and post-treatment.
abstract: Since the discovery of carbon nanotubes (CNTs), scientists have performed extensive studies on nanotubes in the fields of materials science, physics, and electronic engineering. Because multiwalled CNTs (MWCNTs) are not homogeneous materials, and because it is not feasible to test every newly synthesized MWCNT, this study was aimed at investigating the physicochemical properties that primarily determine the cellular toxicity of MWCNTs. This study analyzed the relationship between cell viability and physicochemical characteristics following exposure to eight different MWCNTs. We generated eight different MWCNTs using various synthetic methods and post-treatments. From this analysis, we sought to identify the major physicochemical determinants that could predict the cellular toxicity of MWCNTs, regardless of the synthetic method and post-treatment conditions. Creation of binding sites on the tube walls by breaking C-C bonds played a pivotal role in increasing toxicity and was most clearly demonstrated by a Raman G peak shift and the ID/IG ratio. In addition, several factors were found to be strongly related to cellular toxicity: surface charge in the case of MWCNTs created by the chemical vapor deposition method and surface area and EPR intensity in the case of MWCNTs created by the arc discharge based method. The methods developed in this study could be applied to the prediction of the toxicity of newly synthesized MWCNTs.
authors.affiliation: Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University , Seoul 151-742, Korea.
authors.forename: Ji-Eun
authors.initials: JE
authors.lastname: Kim
authors.forename: Seung-Hyon
authors.initials: SH
authors.lastname: Kang
authors.forename: Youngmi
authors.initials: Y
authors.lastname: Moon
authors.forename: Jin-Joo
authors.initials: JJ
authors.lastname: Chae
authors.forename: Ah Young
authors.initials: AY
authors.lastname: Lee
authors.forename: Jae-Ho
authors.initials: JH
authors.lastname: Lee
authors.forename: Kyeong-Nam
authors.initials: KN
authors.lastname: Yu
authors.forename: Dae Hong
authors.initials: DH
authors.lastname: Jeong
authors.forename: Mansoo
authors.initials: M
authors.lastname: Choi
authors.forename: Myung-Haing
authors.initials: MH
authors.lastname: Cho
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D008670:Metals / Q000032:analysis; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000633:toxicity* / Q000648:ultrastructure; D033362:Powder Diffraction; D013054:Spectrophotometry, Atomic; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013499:Surface Properties; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D008670:Metals; D037742:Nanotubes, Carbon; D000255:Adenosine Triphosphate