Auffan Melanie, Matson Cole W, Rose Jerome, Arnold Mariah, Proux Olivier, Fayard Barbara, Liu Wei, Chaurand Perrine, Wiesner Mark R, Bottero Jean-Yves, Di Giulio Richard T
CNRS, Aix-Marseille Université , CEREGE UM34, UMR 7330, Aix en Provence , France .
Nanotoxicology. 2014 Aug;8 Suppl 1:167-76. doi: 10.3109/17435390.2013.869627. Epub 2013 Dec 20.
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.
我们评估了柠檬酸盐包覆的银纳米颗粒和溶解态银在亚致死浓度下于底鳉胚胎内的生物分布和原位形态。通过全面的物理化学表征，我们研究了盐度对摄取和原位形态的作用。与去离子水（0‰人工海水）相比，河口水中（10‰人工海水）银纳米颗粒的银摄取或在绒毛膜上的吸附减少了2.3倍，硝酸银减少了2.9倍。58%至85%的银定位于绒毛膜上或绒毛膜内，并形成了20至80微米的斑块。绒毛膜不仅是一个物理屏障，还被发现是控制银原位形态的化学反应性膜。在0‰人工海水条件下，柠檬酸盐包覆的银纳米颗粒与绒毛膜蛋白质或酶的硫醇化基团强烈络合，导致48±5%的Ag(0)氧化为Ag((I))-S物种。然而，在10‰人工海水条件下，银纳米颗粒表面Cl(-)离子的存在减缓了这种氧化。对于溶解态银，我们观察到在去离子水中，绒毛膜摄取的Ag(+)中有69±7%被硫醇化分子络合，而其他30±3%可能通过与绒毛膜多糖的半缩醛还原端相互作用被还原为Ag(0)。
