title: Factors affecting the in vitro micronucleus assay for evaluation of nanomaterials.
abstract: A number of in vitro methodologies have been used to assess the genotoxicity of different nanomaterials, including titanium dioxide nanoparticles (TiO2NPs) and silver nanoparticles (AgNPs). The in vitro micronucleus assay is one of the most commonly used test methods for genotoxicity evaluation of nanomaterials. However, due to the novel features of nanomaterials, such as high adsorption capacity and fluorescence properties, there are unexpected interactions with experimental components and detection systems. In this study, we evaluate the interference by two nanoparticles, AgNPs and TiO2NPs, with the in vitro micronucleus assay system and possible confounding factors affecting cytotoxicity and genotoxicity assessment of the nanomaterials including cell lines with different p53 status, nanoparticle coatings and fluorescence, cytochalasin B, fetal bovine serum in cell treatment medium and different measurement methodologies for detecting micronuclei. Our results showed that micronucleus induction by AgNPs was similar when evaluated using flow cytometry or microscope, whereas the induction by TiO2NPs was different using the two methods due to TiO2's fluorescence interference with the cytometry equipment. Cells with the mutated p53 gene were more sensitive to micronucleus induction by AgNPs than the p53 wild-type cells. The presence of serum during treatment increased the toxicity of AgNPs. The coatings of nanoparticles played an important role in the genotoxicity of AgNPs. These collective data highlight the importance of considering the unique properties of nanoparticles in assessing their genotoxicity using the in vitro micronucleus assay.
authors: Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, 3900 NCTR Rd., Jefferson, AR 72079, USA.|Covance Laboratories Inc. 671 S. Meridian Rd., Greenfield, IN 46140, USA.
authors: Yan
authors: Y
authors: Li
authors: Institute of Life Science, Swansea University Medical School, Singleton Park, Swansea SA2 8PP, Wales, UK.
authors: Shareen H
authors: SH
authors: Doak
authors: Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, 3900 NCTR Rd., Jefferson, AR 72079, USA.
authors: Jian
authors: J
authors: Yan
authors: Columbia College, Columbia University in the City of New York, 2960 Broadway, New York, NY 10027, USA and.
authors: David H
authors: DH
authors: Chen
authors: Department of Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, 1881 East Road, Houston, TX 77054, USA.
authors: Min
authors: M
authors: Zhou
authors: Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, 3900 NCTR Rd., Jefferson, AR 72079, USA.
authors: Roberta A
authors: RA
authors: Mittelstaedt
authors: Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, 3900 NCTR Rd., Jefferson, AR 72079, USA.
authors: Ying
authors: Y
authors: Chen
authors: Department of Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, 1881 East Road, Houston, TX 77054, USA.
authors: Chun
authors: C
authors: Li
authors: Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, 3900 NCTR Rd., Jefferson, AR 72079, USA, tao.chen@fda.hhs.gov.
authors: Tao
authors: T
authors: Chen
mesh_terms: D000818:Animals; D002460:Cell Line; D003412:Cricetulus / Q000235:genetics / Q000378:metabolism; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D051379:Mice; D048629:Micronuclei, Chromosome-Defective / Q000139:chemically induced*; D015162:Micronucleus Tests / Q000379:methods*; D009153:Mutagens / Q000494:pharmacology / Q000633:toxicity; D009154:Mutation; D012834:Silver / Q000494:pharmacology / Q000633:toxicity; D014025:Titanium / Q000494:pharmacology / Q000633:toxicity; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*
chemical_list: D009153:Mutagens; D016159:Tumor Suppressor Protein p53; C009495:titanium dioxide; D012834:Silver; D014025:Titanium