title: Salinity-dependent silver nanoparticle uptake and transformation by Atlantic killifish (Fundulus heteroclitus) embryos.
abstract: We assessed the biodistribution and in situ speciation of sub-lethal concentrations of citrate-coated silver nanoparticles and dissolved silver within Fundulus heteroclitus embryos. Using a thorough physico-chemical characterization, we studied the role of salinity on both uptake and in situ speciation. The Ag uptake or adsorption on the chorion was reduced by 2.3-fold for Ag NPs, and 2.9-fold for AgNO3 in estuarine water (10‰ ASW) compared to deionized water (0‰ ASW). Between 58% and 85% of the silver was localized on/in the chorion and formed patches between 20 and 80 µm. More than a physical barrier, the chorion was found to be a chemically reactive membrane controlling the in situ speciation of silver. A strong complexation of the Cit-Ag NPs with the thiolated groups of proteins or enzymes of the chorion was responsible for the oxidation of 48 ± 5% of the Ag(0) into Ag((I))-S species at 0‰ ASW. However, at 10‰ ASW, the presence of Cl(-) ions at the surface of Ag NPs slow down this oxidation. For the dissolved silver, we observed that in deionized water 69 ± 7% of Ag(+) taken up by the chorion was complexed by the thiolated molecules while the others 30 ± 3% were reduced into Ag(0) likely via interaction with the hemiacetal-reducing ends of polysaccharides of the chorion.
authors.affiliation: CNRS, Aix-Marseille Université , CEREGE UM34, UMR 7330, Aix en Provence , France .
authors.forename: Melanie
authors.initials: M
authors.lastname: Auffan
authors.forename: Cole W
authors.initials: CW
authors.lastname: Matson
authors.forename: Jerome
authors.initials: J
authors.lastname: Rose
authors.forename: Mariah
authors.initials: M
authors.lastname: Arnold
authors.forename: Olivier
authors.initials: O
authors.lastname: Proux
authors.forename: Barbara
authors.initials: B
authors.lastname: Fayard
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Perrine
authors.initials: P
authors.lastname: Chaurand
authors.forename: Mark R
authors.initials: MR
authors.lastname: Wiesner
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Bottero
authors.forename: Richard T
authors.initials: RT
authors.lastname: Di Giulio
mesh_terms: D000818:Animals; D023781:Fundulidae / Q000196:embryology / Q000378:metabolism*; D053758:Nanoparticles / Q000737:chemistry / Q000378:metabolism*; D012834:Silver / Q000737:chemistry*; D012965:Sodium Chloride / Q000378:metabolism*
chemical_list: D012834:Silver; D012965:Sodium Chloride
keywords: Chorion; estuarine; nanomaterial; salinity; speciation