title: Embryotoxicity and hair cell toxicity of silver nanoparticles in zebrafish embryos.
abstract: OBJECTIVE
  The purpose of the present study was to evaluate silver nanoparticles (AgNP)-induced embryotoxicity and hair cell toxicity during zebrafish development.
  
  
  METHODS
  We exposed zebrafish embryos to various AgNP concentrations (30, 60, 120, and 240nM) and evaluated embryotoxicity at 72h and ototoxicity at 120h. Embryotoxicity parameters including abnormal morphology, mortality, hatching rate, and heart rate were investigated. Hair cells within four neuromasts were evaluated. In the present study, the average number of hair cells of zebrafish exposed to AgNP was compared with that of an unexposed control group.
  
  
  RESULTS
  The hatching rate was not significantly different between groups (control: 90%; AgNP 240nM: 89%). The control group showed 2% mortality and 0% teratogenicity, while the AgNP 240nM group showed increased mortality (11%) and teratogenicity (15%) at 72h (n=100). The heart rate of AgNP-exposed embryos tended to be lower than that of the control group (n=38). Furthermore, AgNP induced apoptotic hair cell damage in the neuromasts (control: 50.7±7.4 cells; 240nM AgNP: 41.1±6.3 cells, n=23). TUNEL positive cell counts increased significantly as AgNP concentration increases (p<0.001, n=20 in each group).
  
  
  CONCLUSIONS
  The results of this study indicate that AgNP exposure causes embryotoxicity and hair cell toxicity in zebrafish embryos.
authors.affiliation: Department of Otorhinolaryngology - Head and Neck Surgery, Korea University Ansan Hospital, Korea University, College of Medicine, Seoul, Republic of Korea.
authors.forename: Myung Hoon
authors.initials: MH
authors.lastname: Yoo
authors.affiliation: Department of Otorhinolaryngology - Head and Neck Surgery, Korea University Ansan Hospital, Korea University, College of Medicine, Seoul, Republic of Korea.
authors.forename: Yoon Chan
authors.initials: YC
authors.lastname: Rah
authors.affiliation: Department of Otorhinolaryngology - Head and Neck Surgery, Korea University Ansan Hospital, Korea University, College of Medicine, Seoul, Republic of Korea. Electronic address: mednlaw@korea.ac.kr.
authors.forename: June
authors.initials: J
authors.lastname: Choi
authors.affiliation: Department of Otorhinolaryngology - Head and Neck Surgery, Korea University Ansan Hospital, Korea University, College of Medicine, Seoul, Republic of Korea.
authors.forename: Saemi
authors.initials: S
authors.lastname: Park
authors.affiliation: Laboratory of Neurodevelopmental Genetics, Graduate School of Medicine, Korea University, Seoul, Republic of Korea.
authors.forename: Hae-Chul
authors.initials: HC
authors.lastname: Park
authors.affiliation: Department of Otorhinolaryngology - Head and Neck Surgery, Korea University Ansan Hospital, Korea University, College of Medicine, Seoul, Republic of Korea.
authors.forename: Kyoung Ho
authors.initials: KH
authors.lastname: Oh
authors.affiliation: Department of Otorhinolaryngology - Head and Neck Surgery, Korea University Ansan Hospital, Korea University, College of Medicine, Seoul, Republic of Korea.
authors.forename: Seung Hoon
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Otorhinolaryngology - Head and Neck Surgery, Korea University Ansan Hospital, Korea University, College of Medicine, Seoul, Republic of Korea.
authors.forename: Soon-Young
authors.initials: SY
authors.lastname: Kwon
mesh_terms: D000818:Animals; D004625:Embryo, Nonmammalian / Q000187:drug effects*; D006197:Hair; D006198:Hair Cells, Auditory / Q000187:drug effects*; D020287:In Situ Nick-End Labeling; D053768:Metal Nanoparticles / Q000633:toxicity*; D012834:Silver / Q000633:toxicity*; D064793:Teratogenesis; D015027:Zebrafish / Q000196:embryology*
chemical_list: D012834:Silver
keywords: Embryotoxicity; Hair cell; Silver nanoparticles; Teratogenicity; Zebrafish