title: Evaluation of genotoxicity of multi-walled carbon nanotubes in a battery of in vitro and in vivo assays.
abstract: The genotoxic potential of two products of multi-walled carbon nanotubes (coded as N-MWCNTs, diameter of 44 nm/BET surface area of 69 m²/g and MWNT-7, diameter of 70 nm/BET surface area of 23 m²/g) was evaluated using a battery of genotoxicity assays, comprising a bacterial reverse mutation test, an in vitro mammalian chromosomal aberration test, and a mammalian erythrocytes micronucleus test. Neither type exerted mutagenicity in Salmonella typhimurium TA98, TA100, TA1535, and TA1537, or in Escherichia coli WP2uvrA, in the absence or presence of metabolic activation. The products of MWCNTs did not increase the number of structural chromosomal aberrations either, regardless of metabolic activation, though they increased the number of numerical chromosomal aberrations, one slightly and the other distinctly, in the absence of metabolic activation. In ICR mice, the two products did not affect the proportion of immature erythrocytes, the total proportion of erythrocytes, or the number of micronuclei in immature erythrocytes.
authors.affiliation: Research Institute of Science for Safety and Sustainability, National Institute of Advanced Industrial Science and Technology-AIST, Ibaraki 305-8569, Japan. ema-makoto@aist.go.jp
authors.forename: Makoto
authors.initials: M
authors.lastname: Ema
authors.forename: Tadashi
authors.initials: T
authors.lastname: Imamura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suzuki
authors.forename: Norihiro
authors.initials: N
authors.lastname: Kobayashi
authors.forename: Masato
authors.initials: M
authors.lastname: Naya
authors.forename: Junko
authors.initials: J
authors.lastname: Nakanishi
mesh_terms: D000818:Animals; D002460:Cell Line; D002869:Chromosome Aberrations / Q000139:chemically induced*; D006224:Cricetinae; D003412:Cricetulus; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000187:drug effects / Q000648:ultrastructure; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D005260:Female; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D048629:Micronuclei, Chromosome-Defective / Q000139:chemically induced; D008855:Microscopy, Electron, Scanning; D009152:Mutagenicity Tests / Q000379:methods; D009153:Mutagens / Q000737:chemistry / Q000633:toxicity*; D009154:Mutation; D037742:Nanotubes, Carbon / Q000737:chemistry / Q000633:toxicity*; D010316:Particle Size; D051381:Rats; D017207:Rats, Sprague-Dawley; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D013054:Spectrophotometry, Atomic; D013499:Surface Properties
chemical_list: D009153:Mutagens; D037742:Nanotubes, Carbon