Enea CR Portici, P. le E. Fermi, 1, 80055 Portici, Naples, Italy.
Dep. Zoology and Animal Cell Biology, Faculty of Science and Technology and Research Centre for Experimental Marine Biology and Biotechnology (PIE), University of the Basque Country (UPV/EHU), 48940 Leioa, Basque Country, Spain.
Sci Total Environ. 2017 Jan 15;577:45-53. doi: 10.1016/j.scitotenv.2016.10.051. Epub 2016 Oct 15.
In the last years, applications for silver nanoparticles (Ag NPs) continue to increase together with the concerns about their potential input and hazards in aquatic ecosystems, where microalgae are key organisms. The aim of the present study was to assess the relative sensitivity of three marine microalgae species with differences in cell wall composition/structure exposed to Poly N-vinyl-2-pirrolidone/Polyethyleneimine (PVP/PEI) coated 5nm Ag NPs and uncoated 47nm Ag NP. As limited attention has been paid to the role of coating agents in NP toxicity, the effect of PVP/PEI alone was also evaluated. After 72h in artificial seawater, 47nm Ag NPs formed around 1400nm size aggregates while PVP/PEI coated 5nm Ag NPs reached around 90nm. Ag release in seawater was around 3% for 47nm Ag NPs and 30% for PVP/PEI coated 5nm Ag NPs. PVP/PEI coated 5nm Ag NP aggregates entrapped the algal cells in a network of heteroaggregates, while uncoated 47nm Ag NPs interacted to a lesser extent with algae. The concentration of PVP/PEI coated 5nm Ag NPs that exerted the median effect (EC50) on algae growth pointed out differences in algae sensitivity: T. suecica was about 10 times more sensitive than I. galbana and P. tricornutum. Further, the coating agent alone was as toxic to algae as PVP/PEI coated 5nm Ag NPs, suggesting that presence of the coating agent was the main driver of toxicity of coated NPs. Uncoated 47nm Ag NPs instead, showed similar toxicity towards algae although P. tricornutum was slightly less sensitive than T. suecica and I. galbana, which agrees with the presence of a resistant silicified cell wall in the diatom. The present work demonstrates differences in sensitivity of three marine microalgae, possibly related to their cell surface and size characteristics.
在过去的几年中，银纳米粒子（Ag NPs）的应用不断增加，同时人们对其在水生生态系统中的潜在输入和危害也越来越关注，而微藻是这些生态系统中的关键生物。本研究的目的是评估三种具有细胞壁组成/结构差异的海洋微藻对涂有聚 N-乙烯基-2-吡咯烷酮/聚乙烯亚胺（PVP/PEI）的 5nm Ag NPs 和未涂覆的 47nm Ag NP 的相对敏感性。由于人们对涂层剂在纳米粒子毒性中的作用关注有限，因此还评估了 PVP/PEI 单独的作用。在人工海水中培养 72 小时后，47nm Ag NPs 形成了约 1400nm 大小的团聚体，而 PVP/PEI 涂覆的 5nm Ag NPs 则达到了约 90nm。在海水中，47nm Ag NPs 的银释放量约为 3%，而 PVP/PEI 涂覆的 5nm Ag NPs 的银释放量约为 30%。PVP/PEI 涂覆的 5nm Ag NP 团聚物将藻类细胞困在异质团聚体的网络中，而未涂覆的 47nm Ag NPs 与藻类的相互作用则较小。对藻类生长产生中值效应（EC50）的 PVP/PEI 涂覆的 5nm Ag NP 浓度表明藻类敏感性存在差异：T. suecica 比 I. galbana 和 P. tricornutum 敏感约 10 倍。此外，单独的涂层剂对藻类的毒性与 PVP/PEI 涂覆的 5nm Ag NPs 一样，这表明涂层剂的存在是涂覆纳米粒子毒性的主要驱动因素。相反，未涂覆的 47nm Ag NPs 对藻类表现出相似的毒性，尽管 P. tricornutum 比 T. suecica 和 I. galbana 略不敏感，这与硅藻中存在抗硅化细胞壁一致。本工作证明了三种海洋微藻的敏感性存在差异，这可能与其细胞表面和大小特征有关。
