Agglomeration of tungsten carbide nanoparticles in exposure medium does not prevent uptake and toxicity toward a rainbow trout gill cell line
Agglomeration of tungsten carbide nanoparticles in exposure medium does not prevent uptake and toxicity toward a rainbow trout gill cell line
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DOI：
10.1016/j.aquatox.2009.04.003
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发表时间：
2009-06-28
影响因子：
4.5
通讯作者：
Schirmer, Kristin
中科院分区：
文献类型：
--
作者：
Kuehnel, Dana;Busch, Wibke;Schirmer, Kristin
由于其生产和使用的增加，预计工程纳米颗粒将被释放到颗粒可能聚集的水生环境中。本研究的目的是探讨凝聚的纳米粒子在虹鳟鱼（Oncorhynchus mykiss）鳃细胞系，RTgill-W1的毒性的吸收和表达的作用。选择该细胞系作为模型，因为已知其适合在完全以及大大简化的暴露培养基中培养。纳米尺寸的碳化钨（WC）与或不掺杂钴（WC-Co），两种材料相关的重金属工业，被应用作为模型颗粒。将这些颗粒悬浮在复杂性从含10%胎牛血清（FBS）的L15到L15/ex逐渐降低的培养基中，所述培养基仅含有完全培养基L15的盐、半乳糖和丙酮酸盐。尽管L15中的血清补充剂保留初级纳米颗粒悬浮液，但在L15和L15/ex中快速形成附聚物。然而，扫描电子显微镜（SEM）加上能量色散X-射线（EDX）元素分析显示，无论纳米颗粒的团聚状态如何，WC和WC-Co纳米颗粒都被摄取到RTgill-W1细胞中。定位似乎仅限于细胞质，因为在细胞核中未观察到颗粒。此外，与对照相比，在所有培养基中暴露于颗粒后观察到细胞活力降低10 - 50%，尽管影响模式取决于培养基和暴露时间。在最高标称颗粒浓度下，细胞短期暴露导致显著的细胞毒性，与颗粒类型或暴露介质无关。相反，长期暴露导致在最简单的介质，L15/ex中的优先毒性，并在所有暴露介质中的含钴WC纳米颗粒的毒性增强。暴露介质的组成也影响了钴离子的毒性，钴离子可能从WC-Co纳米颗粒中溶解，在没有FBS的情况下，细胞对钴离子的反应更加敏感。然而，观察到的毒性离子钴单独没有解释的WC-钴纳米粒子的毒性，这表明金属钴和WC的组合是WC-钴的颗粒毒性增加的原因。两者合计，我们的研究结果表明，最低限度的曝光媒体可以导致纳米粒子的快速团聚，但团聚并不能阻止摄取到细胞和毒性的表达。(C)2009 Elsevier B. V.保留所有权利。
Due to their increased production and use, engineered nanoparticles are expected to be released into the aquatic environment where particles may agglomerate. The aim of this study was to explore the role of agglomeration of nanoparticles in the uptake and expression of toxicity in the rainbow trout (Oncorhynchus mykiss) gill cell line, RTgill-W1. This cell line was chosen as model because it is known to be amenable to culture in complete as well as greatly simplified exposure media. Nano-sized tungsten carbide (WC) with or without cobalt doping (WC-Co), two materials relevant in the heavy metal industry, were applied as model particles. These particles were Suspended in culture media with decreasing complexity from L15 with 10% fetal bovine serum (FBS) to L15 to L15/ex, containing only salts, galactose and pyruvate of the complete medium L15. Whereas the serum supplement in L15 retained primary nanoparticle suspensions, agglomerates were formed quickly in L15 and L15/ex. Nevertheless, scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) elemental analysis revealed an uptake of both WC and WC-Co nanoparticles into RTgill-W1 cells irrespective of the state of agglomeration of nanoparticles. The localisation seemed to be restricted to the cytoplasm, as no particles were observed in the nucleus of cells. Moreover, reduction in cell viability between 10 and 50% compared to controls were observed upon particle exposure in all media although the pattern of impact varied depending on the medium and exposure time. Short-term exposure of cells led to significant cytotoxicity at the highest nominal particle concentrations, irrespective of the particle type or exposure medium. In contrast, long-term exposures led to preferential toxicity in the simplest medium, L15/ex, and an enhanced toxicity by the cobalt-containing WC nanoparticles in all exposure media. The composition of the exposure media also influenced the toxicity of the cobalt ions, which may dissolve from the WC-Co nanoparticles, with cells reacting much more sensitively toward cobalt ions in the absence of FBS. However, the toxicity observed by ionic cobalt alone did not explain the toxicity of the WC-Co nanoparticles, suggesting that the combination of metallic Co and WC is the cause of the increased particle toxicity of WC-Co. Taken together, our findings indicate that minimal exposure media can lead to rapid agglomeration of nanoparticles but that agglomeration does not prevent uptake into cells and the expression of toxicity. (C) 2009 Elsevier B.V. All rights reserved.