Khan Ashfeen Ubaid, Xu Zhenlan, Qian Xiaoting, Hong Aimei, Tang Qing, Zeng Tao, Kah Melanie, Li Lingxiangyu
Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China.
Institute of Quality and Standard of Agro-Products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
J Hazard Mater. 2021 Jan 5;401:123406. doi: 10.1016/j.jhazmat.2020.123406. Epub 2020 Jul 4.
Engineered silver sulfide nanoparticles (e-AgS-NPs) are used in industry and can be released into the environment. Besides e-AgS-NPs, transformed silver sulfide nanoparticles (t-AgS-NPs) from silver nanoparticles are more likely to be the form that is widely distributed in the environment. Both e-AgS-NPs and t-AgS-NPs may be ingested and get into human gastrointestinal tract (GIT) through trophic transfer, posing a potential threat to human health. Nevertheless, knowledge of chemical stability of t-AgS-NPs and e-AgS-NPs in the human GIT is very limited. Herein e-AgS-NPs and a series of t-AgS-NPs with different degrees of sulfidation were selected as models for exposure to the simulated human GIT including mouth, stomach and small intestine phases under fed and fasted conditions. Silver ions were detected in the simulated saliva, gastric and small intestine fluids when t-AgS-NPs or e-AgS-NPs were incubated in the simulated GIT, but the amount (e.g., < 20 μg) of silver ion in each phase accounted for < 0.2‰ (w/w) of the silver added (i.e., 100 mg). Silver species of the residual particulate from each phase of the simulated GIT with t-AgS-NPs or e-AgS-NPs were thus analyzed through a developed analytical method that could selectively, successively and efficiently dissolve and quantify AgCl, Ag(0), and AgS in particulates. Both e-AgS-NPs and fully sulfidized t-AgS-NPs were shown to be highly stable in the simulated human GIT. Conversely, partially sulfidized t-AgS-NPs primarily underwent transformations in the mouth phase relative to stomach and small intestine phases regardless of fed or fasted status, wherein AgCl and AgS were observed besides Ag(0). The amount of AgS in the mouth phase negatively (r = -0.99, p < 0.001) correlated with the sulfidation degree of initial t-AgS-NPs. This work improved our understanding of potential transformations of t-AgS-NPs in the simulated human GIT, providing valuable information for future researches on evaluating health risks of ingested AgS-NPs.
工程硫化银纳米颗粒（e-AgS-NPs）被应用于工业领域，并且可能释放到环境中。除了e-AgS-NPs外，由银纳米颗粒转化而来的硫化银纳米颗粒（t-AgS-NPs）更有可能是广泛分布于环境中的形态。e-AgS-NPs和t-AgS-NPs都可能被摄入，并通过营养转移进入人体胃肠道（GIT），对人类健康构成潜在威胁。然而，关于t-AgS-NPs和e-AgS-NPs在人体胃肠道中的化学稳定性的了解非常有限。在此，选择e-AgS-NPs和一系列不同硫化程度的t-AgS-NPs作为模型，在进食和空腹条件下模拟人体胃肠道的口腔、胃和小肠阶段进行暴露实验。当t-AgS-NPs或e-AgS-NPs在模拟胃肠道中孵育时，在模拟唾液、胃液和小肠液中检测到了银离子，但各阶段银离子的量（如<20μg）占添加银量（即100mg）的<0.2‰（w/w）。因此，通过一种开发的分析方法对含有t-AgS-NPs或e-AgS-NPs的模拟胃肠道各阶段的残留颗粒中的银物种进行了分析，该方法可以选择性地、连续地和有效地溶解并定量颗粒中的AgCl、Ag(0)和AgS。结果表明，e-AgS-NPs和完全硫化的t-AgS-NPs在模拟人体胃肠道中都具有高度稳定性。相反，无论进食或空腹状态如何，部分硫化的t-AgS-NPs在口腔阶段相对于胃和小肠阶段主要发生转化，其中除了Ag(0)外还观察到了AgCl和AgS。口腔阶段AgS的量与初始t-AgS-NPs的硫化程度呈负相关（r = -0.99，p < 0.001）。这项工作增进了我们对t-AgS-NPs在模拟人体胃肠道中潜在转化的理解，为未来评估摄入AgS-NPs的健康风险的研究提供了有价值的信息。
