University of Pardubice, Faculty of Chemical Technology, Institute of Environmental and Chemical Engineering, 53210 Pardubice, Czech Republic; Eawag - Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland.
University of Pardubice, Faculty of Chemical Technology, Department of General and Inorganic Chemistry, 53210 Pardubice, Czech Republic.
Aquat Toxicol. 2021 Aug;237:105869. doi: 10.1016/j.aquatox.2021.105869. Epub 2021 May 16.
Silver nanoparticles (Ag NPs) are widely used in consumer products especially because of their antimicrobial properties. However, this wide usage of Ag NPs is accompanied by their release into the environment where they will be rapidly transformed to other silver species - especially silver sulfide (AgS). In the present study, we synthesized Ag NPs and sulfidized them to obtain a core-shell system Ag@AgS NPs. Both types of particles form stable dispersions with hydrodynamic diameters of less than 100 nm when diluted in water, but tend to form micrometer-sized agglomerates in biological exposure media. Application of Ag and Ag@AgS NPs to rainbow trout intestinal cells (RTgutGC) resulted in a concentration-dependent cytotoxicity for both types of particles, as assessed by a three-endpoint assay for metabolic activity, membrane integrity and lysosomal integrity. The Ag NPs were shown to be slightly more toxic than the Ag@AgS NPs. Adding Ag or Ag@AgS NPs to RTgutGC cells, grown on a permeable membrane to mimic the intestinal barrier, revealed considerable accumulation of silver for both types of particles. Indeed, the cells significantly attenuated the NP translocation, allowing only a fraction of the metal to translocate across the intestinal epithelium. These findings support the notion that the intestine constitutes an important sink for Ag NPs and that, despite the reduced cytotoxicity of a sulfidized NP form, the particles can enter fish where they may constitute a long-term source for silver ion release and cytotoxicity.
银纳米粒子（Ag NPs）由于其抗菌性能而被广泛应用于消费产品中。然而，Ag NPs 的广泛使用伴随着它们被释放到环境中，在环境中它们将迅速转化为其他银物种 - 特别是硫化银（AgS）。在本研究中，我们合成了 Ag NPs 并对其进行硫化，以获得核壳结构的 Ag@AgS NPs。这两种类型的粒子在水中稀释时形成稳定的分散体，其水动力学直径小于 100nm，但在生物暴露介质中倾向于形成微米级的团聚体。将 Ag 和 Ag@AgS NPs 应用于虹鳟鱼肠细胞（RTgutGC），通过三终点测定法评估代谢活性、膜完整性和溶酶体完整性，发现这两种类型的粒子均具有浓度依赖性的细胞毒性。Ag NPs 比 Ag@AgS NPs 略具毒性。将 Ag 或 Ag@AgS NPs 添加到 RTgutGC 细胞上，这些细胞生长在可模拟肠道屏障的渗透膜上，发现这两种类型的粒子都有相当数量的银积累。事实上，细胞显著抑制了 NP 的转运，只有一部分金属能够穿过肠道上皮转运。这些发现支持了这样一种观点，即肠道是 Ag NPs 的一个重要汇，尽管硫化 NP 形式的细胞毒性降低，但这些粒子可以进入鱼类体内，在鱼类体内它们可能成为银离子释放和细胞毒性的长期来源。
