title: Influence of length on cytotoxicity of multi-walled carbon nanotubes against human acute monocytic leukemia cell line THP-1 in vitro and subcutaneous tissue of rats in vivo.
abstract: Carbon nanotubes (CNTs) are single- or multi-cylindrical graphene structures that possess diameters of a few nanometers, while the length can be up to a few micrometers. These could have unusual toxicological properties, in that they share intermediate morphological characteristics of both fibers and nanoparticles. To date, no detailed study has been carried out to determine the effect of length on CNT cytotoxicity. In this paper, we investigated the activation of the human acute monocytic leukemia cell line THP-1 in vitro and the response in subcutaneous tissue in vivo to CNTs of different lengths. We used 220 nm and 825 nm-long CNT samples for testing, referred to as "220-CNTs" and "825-CNTs", respectively. 220-CNTs and 825-CNTs induced human monocytes in vitro, although the activity was significantly lower than that of microbial lipopeptide and lipopolysaccharide, and no activity appeared following variation in the length of CNTs. On the other hand, the degree of inflammatory response in subcutaneous tissue in rats around the 220-CNTs was slight in comparison with that around the 825-CNTs. These results indicated that the degree of inflammation around 825-CNTs was stronger than that around 220-CNTs since macrophages could envelop 220-CNTs more readily than 825-CNTs. However, no severe inflammatory response such as necrosis, degeneration or neutrophil infiltration in vivo was observed around both CNTs examined throughout the experimental period.
authors.affiliation: Graduate School of Environmental Studies, Tohoku University, Aramaki, Sendai, Japan. hige@bucky1.kankyo.tohoku.ac.jp
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Sato
authors.forename: Atsuro
authors.initials: A
authors.lastname: Yokoyama
authors.forename: Ken-ichiro
authors.initials: K
authors.lastname: Shibata
authors.forename: Yuki
authors.initials: Y
authors.lastname: Akimoto
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Ogino
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Nodasaka
authors.forename: Takao
authors.initials: T
authors.lastname: Kohgo
authors.forename: Kazuchika
authors.initials: K
authors.lastname: Tamura
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Akasaka
authors.forename: Motohiro
authors.initials: M
authors.lastname: Uo
authors.forename: Kenichi
authors.initials: K
authors.lastname: Motomiya
authors.forename: Balachandran
authors.initials: B
authors.lastname: Jeyadevan
authors.forename: Mikio
authors.initials: M
authors.lastname: Ishiguro
authors.forename: Rikizo
authors.initials: R
authors.lastname: Hatakeyama
authors.forename: Fumio
authors.initials: F
authors.lastname: Watari
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Tohji
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D007249:Inflammation / Q000209:etiology; D007948:Leukemia, Monocytic, Acute / Q000378:metabolism / Q000473:pathology; D008297:Male; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000633:toxicity; D051381:Rats; D017208:Rats, Wistar; D013055:Spectrophotometry, Infrared; D040521:Subcutaneous Tissue / Q000473:pathology / Q000648:ultrastructure; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D003470:Culture Media; D037742:Nanotubes, Carbon; D014409:Tumor Necrosis Factor-alpha