The utility of the in vitro micronucleus test for evaluating the genotoxicity of natural and manmade nano-scale fibres.
A range of fibrous materials, including several types of asbestos and carbon fibres with nano scale diameters that had reported positive genotoxicity data (predominantly clastogenicity), were tested in the in vitro micronucleus test (OECD 487) in GLP-compliant studies in Chinese Hamster Ovary cells. Out of eight materials tested, only one (crocidolite, an asbestos fibre) gave a positive response either in the presence or absence of metabolic activation (S9) and at short (3h) or extended (24h) exposure times (p≤0.001). Our data suggest that the commonly used tests for clastogenicity in mammalian cells require extensive modification before fibrous materials are detected as positive, raising questions about the validity of these tests for detecting clastogenic and aneugenic fibrous materials.
Unilever, Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedfordshire, MK44 1LQ, UK. Electronic address: paul.fowler@unilever.com.
Paul
P
Fowler
Unilever, Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedfordshire, MK44 1LQ, UK. Electronic address: Andrew.Homan@unilever.com.
Andrew
A
Homan
Unilever Strategic Science Group Colworth Science Park, Sharnbrook, Bedfordshire, MK44 1LQ, UK. Electronic address: Derek.Atkins@unilever.com.
Derek
D
Atkins
Covance Laboratories Ltd., Otley Road, Harrogate HG3 1PY, UK. Electronic address: James.Whitwell@covance.com.
James
J
Whitwell
Covance Laboratories Ltd., Otley Road, Harrogate HG3 1PY, UK. Electronic address: Mel.lloyd@covance.com.
Melvyn
M
Lloyd
Unilever, Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedfordshire, MK44 1LQ, UK. Electronic address: Bobbie.Bradford@unilever.com.
Roberta
R
Bradford
D000818:Animals; D001194:Asbestos / Q000633:toxicity; D016466:CHO Cells; D002244:Carbon / Q000633:toxicity; D002869:Chromosome Aberrations / Q000187:drug effects; D006224:Cricetinae; D003412:Cricetulus; D004249:DNA Damage / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D015162:Micronucleus Tests / Q000379:methods*; D009152:Mutagenicity Tests / Q000379:methods / Q000706:statistics & numerical data*; D009153:Mutagens / Q000633:toxicity*; D057139:Nanofibers / Q000633:toxicity*
D009153:Mutagens; D001194:Asbestos; D002244:Carbon
Fibre; Genotoxicity; Human cells; Nano material; Sensitivity