title: Undetactable levels of genotoxicity of SiO2 nanoparticles in in vitro and in vivo tests.
abstract: BACKGROUND
  Silica dioxide (SiO2) has been used in various industrial products, including paints and coatings, plastics, synthetic rubbers, and adhesives. Several studies have investigated the genotoxic effects of SiO2; however, the results remain controversial due to variations in the evaluation methods applied in determining its physicochemical properties. Thus, well characterized chemicals and standardized methods are needed for better assessment of the genotoxicity of nanoparticles.
  
  
  METHODS
  The genotoxicity of SiO2 was evaluated using two types of well characterized SiO2, ie, 20 nm (-) charge (SiO (EN20(-))2) and 100 nm (-) charge (SiO (EN100(-))2). Four end point genotoxicity tests, ie, the bacterial mutation assay, in vitro chromosomal aberration test, in vivo comet assay, and in vivo micronucleus test, were conducted following the test guidelines of the Organization for Economic Cooperation and Development (OECD) with application of Good Laboratory Practice.
  
  
  RESULTS
  No statistically significant differences were found in the bacterial mutation assay, in vitro chromosomal aberration test, in vivo comet assay, and in vivo micronucleus test when tested for induction of genotoxicity in both two types of SiO2 nanoparticles.
  
  
  CONCLUSIONS
  These results suggest that SiO2 nanoparticles, in particular SiO2 (EN20(-)) and SiO2 (EN100(-)), are not genotoxic in both in vitro and in vivo systems under OECD guidelines. Further, the results were generated in accordance with OECD test guidelines, and Good Laboratory Practice application; it can be accepted as reliable information regarding SiO2-induced genotoxicity.
authors.affiliation: Department of Life Science, Institute of Environmental Medicine, Dongguk University, Seoul, Republic of Korea.
authors.forename: Jee Young
authors.initials: JY
authors.lastname: Kwon
authors.affiliation: Department of Life Science, Institute of Environmental Medicine, Dongguk University, Seoul, Republic of Korea.
authors.forename: Hye Lim
authors.initials: HL
authors.lastname: Kim
authors.affiliation: Korea Testing and Research Institute, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jong Yun
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Korea Testing and Research Institute, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Yo Han
authors.initials: YH
authors.lastname: Ju
authors.affiliation: Korea Testing and Research Institute, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Ji Soo
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Life Science, Institute of Environmental Medicine, Dongguk University, Seoul, Republic of Korea.
authors.forename: Seung Hun
authors.initials: SH
authors.lastname: Kang
authors.affiliation: Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Yu-Ri
authors.initials: YR
authors.lastname: Kim
authors.affiliation: Toxicological Research Division, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Chungcheongbuk-do, Republic of Korea.
authors.forename: Jong-Kwon
authors.initials: JK
authors.lastname: Lee
authors.affiliation: Toxicological Research Division, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Chungcheongbuk-do, Republic of Korea.
authors.forename: Jayoung
authors.initials: J
authors.lastname: Jeong
authors.affiliation: Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Meyoung-Kon
authors.initials: MK
authors.lastname: Kim
authors.affiliation: Korea Testing and Research Institute, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Eun Ho
authors.initials: EH
authors.lastname: Maeng
authors.affiliation: Department of Life Science, Institute of Environmental Medicine, Dongguk University, Seoul, Republic of Korea.
authors.forename: Young Rok
authors.initials: YR
authors.lastname: Seo
mesh_terms: D000818:Animals; D001419:Bacteria / Q000187:drug effects; D002460:Cell Line; D006224:Cricetinae; D004249:DNA Damage / Q000187:drug effects; D009152:Mutagenicity Tests; D053758:Nanoparticles / Q000032:analysis / Q000633:toxicity; D051381:Rats; D017207:Rats, Sprague-Dawley; D012822:Silicon Dioxide / Q000032:analysis / Q000633:toxicity
chemical_list: D012822:Silicon Dioxide
keywords: Good Laboratory Practice; Organization for Economic Cooperation and Development test guideline; genotoxicity test; silica dioxide