Selenium nanoparticles (nano-Se) have a wide range of biomedical and agricultural applications. However, there is little information on the potential toxicity of nano-Se once it enters the environment, particularly in fish. The first line of defense from contaminants that embryonic fish have is the chorion, but the degree to which the chorion protects the developing embryo is unknown. Japanese medaka (Oryzias latipes) embryos were exposed to nano-Se in a wide range of concentrations (0.1-400 µM). The importance of chorion integrity was evaluated by exposing embryos to 16 nm nano-Se under four degrees of dechorionation: intact, roughened, partially-dechorionated, fully-dechorionated. Then, effects of particle size on embryos and larvae were determined using four sizes of nano-Se particles (16, 25-50, 50, 100 nm). The results showed that nano-Se exposure reduced survival, development, and hatching. Nano-Se was observed to adsorb on the chorion, with the amount decreasing with increased degree of dechorionation. Toxicity increased with increasing degree of dechorionation, and smaller-sized nano-Se crossed intact chorion more readily and resulted in higher toxicity than larger ones. In larvae, nano-Se accumulated on the skin and was more toxic compared to embryos. This study demonstrated the importance of the chorion in protecting developing embryos and effects of nanoparticle size on its bioavailability and subsequent toxicity.

中文翻译：

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绒毛膜完整性对日本青鳉 （Oryzias latipes） 中硒纳米颗粒生物积累和毒性的作用


硒纳米颗粒 （nano-Se） 具有广泛的生物医学和农业应用。然而，关于纳米硒进入环境后的潜在毒性的信息很少，尤其是在鱼类中。胚胎鱼抵御污染物的第一道防线是绒毛膜，但绒毛膜保护发育中的胚胎的程度尚不清楚。日本青鳉 （Oryzias latipes） 胚胎暴露于宽浓度范围 （0.1-400 μM） 的纳米硒中。通过在四种去绒毛度下将胚胎暴露于 16 nm 纳米硒来评估绒毛膜完整性的重要性：完整、粗糙、部分去绒毛膜、完全去绒毛膜。然后，使用四种尺寸的纳米硒颗粒 （16、25-50、50、100 nm） 确定粒径对胚胎和幼虫的影响。结果表明，纳米硒暴露降低了存活率、发育和孵化率。观察到 Nano-Se 吸附在绒毛膜上，随着去绒毛膜程度的增加，其量减少。毒性随着去绒毛膜程度的增加而增加，较小尺寸的 nano-Se 更容易穿过完整的绒毛膜，并导致比较大的绒毛膜更高的毒性。在幼虫中，纳米硒积聚在皮肤上，与胚胎相比毒性更大。这项研究表明了绒毛膜在保护发育中的胚胎方面的重要性以及纳米颗粒大小对其生物利用度和后续毒性的影响。