title: The role of chorion on toxicity of silver nanoparticles in the embryonic zebrafish assay.
abstract: OBJECTIVE
  This study was designed to investigate how the size- and surface coating-dependent toxicity of silver nanoparticles (AgNPs) is influenced by the presence and absence of the chorion in an embryonic zebrafish assay.
  
  
  METHODS
  Normal and dechorinated embryos were exposed to four different AgNPs, 20 or 110 nm in size, with polypyrrolidone (PVP) or citrate surface coatings in a standard zebrafish embryo medium (EM). This was then compared to a 62.5 μM calcium chloride (CaCl2) solution where agglomeration was controlled.
  
  
  RESULTS
  Embryonic toxicity in the absence of the chorion was greater than in its presence. The smaller 20 nm AgNPs were more toxic than the larger 110 nm AgNPs, regardless of the chorion and test media. However, surface coating affected toxicity, since PVPcoated AgNPs were more toxic than citrate-coated AgNPs; this was strongly affected by the presence of the chorion in both EM and CaCl2.
  
  
  CONCLUSIONS
  Our results demonstrate the permeability function of the chorion on the size- and surface coating-dependent toxicity of AgNPs. Thereafter, careful experiment should be conducted to assess nanoparticle toxicity in zebrafish embryos.
authors.affiliation: Department of Environmental Engineering, Seoul National University of Science and Technology, Seoul, Korea.
authors.forename: Ki-Tae
authors.initials: KT
authors.lastname: Kim
authors.affiliation: Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Tanguay
keywords: Chorion; Silver nanoparticles; Zebrafish