The concentration-dependent aggregation of Ag NPs induced by cystine
The concentration-dependent aggregation of Ag NPs induced by cystine
复制标题
DOI：
10.1016/j.scitotenv.2016.02.212
复制
发表时间：
2016-07-01
影响因子：
9.8
通讯作者：
Baalousha, M.
中科院分区：
文献类型：
--
作者：
Afshinnia, K.;Gibson, I.;Baalousha, M.
胱氨酸广泛用于细胞培养基中。半胱氨酸是胱氨酸的还原形式，在生态毒理学研究中广泛用于溶解银，以区分溶解的与纳米颗粒的吸收和毒性。然而，关于半胱氨酸和胱氨酸对Ag NP的聚集行为的影响，特别是作为Ag NP浓度的函数，知之甚少。在此，我们研究了胱氨酸（0-300 μ M）如何影响柠檬酸盐-、聚乙烯吡咯烷酮-和聚乙二醇-涂覆的银纳米颗粒（分别为cit-Ag纳米颗粒、PVP-Ag纳米颗粒和PEG-Ag纳米颗粒）的稳定性，其具有和不具有Suwannee河富里酸（SRFA），作为Ag纳米颗粒浓度的函数，使用紫外可见光谱在环境和生态毒理学相关的Ag纳米颗粒浓度下（约100 μ M）。1251000 μ g L ~（-1）。结果首次证明了在胱氨酸存在下cit-Ag NP的浓度依赖性聚集，在较低cit-Ag NP浓度下，临界凝血浓度（CCC）向较低胱氨酸浓度偏移。在最高cit-Ag NP浓度（1000 μ g L-1）下，仅观察到反应限制性聚集，未测量到CCC。SRFA可抑制胱氨酸对cit-Ag纳米粒子的聚集，且仅在反应限制性聚集（RLA）模式下发生聚集。在SRFA存在下未测量CCC值。胱氨酸取代柠檬酸盐、PVP和PEG涂层，导致静电和空间稳定的Ag NP两者的聚集。这些发现对于理解决定Ag NPs在细胞培养基中的行为的因素是重要的。同样由于胱氨酸和半胱氨酸之间的相似性，这些结果对于理解Ag NP相对于Ag离子的吸收和毒性是重要的，并且表明在半胱氨酸存在下Ag NP的毒性的降低可能是由于在半胱氨酸存在下清除Ag+离子和Ag NP聚集的组合效应。(C)© 2016 Elsevier B. V.版权所有。
Cystine is widely used in cell culture media. Cysteine, the reduced form of cystine, is widely used to scavenge dissolved Ag in eco-toxicological studies to differentiate dissolved vs. nanoparticle uptake and toxicity. However, little is known about the impact of cysteine and cystine on the aggregation behavior of Ag NPs, in particular as a function of Ag NP concentration. Herein, we investigate how cystine (0-300 mu M) affects the stability of citrate-, polyvinylpyrrolidone-, and polyethylene glycol-coated silver nanoparticles (cit-Ag NPs, PVP-Ag NPs and PEG-Ag NPs, respectively) with and without Suwannee River fulvic acid (SRFA) as a function of Ag NPs concentration using UV-vis spectroscopy at environmentally and ecotoxicologically relevant Ag NP concentrations (ca. 1251000 mu g L-1). The results demonstrate, for the first time, the concentration-dependent aggregation of cit-Ag NPs in the presence of cystine with a shift in the critical coagulation concentration (CCC) to lower cystine concentrations at lower cit-Ag NP concentrations. At the highest cit-Ag NP concentration (1000 mu g L-1), reaction limited aggregation was only observed and no CCC was measured. SRFA slowed the aggregation of cit-Ag NPs by cystine and aggregation occurred in reaction limited aggregation (RLA) regime only. No CCC value was measured in the presence of SRFA. Cystine replaces citrate, PVP and PEG coatings, resulting in aggregation of both electrostatically and sterically stabilized Ag NPs. These findings are important in understanding the factors determining the behavior of Ag NPs in cell culture media. Also due to the similarity between cystine and cysteine, these results are important in understanding the uptake and toxicity of Ag NPs vs. Ag ions, and suggest that the reduction of the toxicity of Ag NPs in the presence of cysteine could be due to a combined effect of scavenging Ag+ ions and Ag NP aggregation in the presence of cysteine. (C) 2016 Elsevier B.V. All rights reserved.