CSIC, Spanish National Reference Laboratory for Mollusc Diseases, Instituto de Investigaciones Marinas, 36208, Vigo, Spain; Department of Ecology and Coastal Management, Institute of Marine Sciences of Andalusia (CSIC), Campus Río San Pedro, 11510, Puerto Real, Cádiz, Spain.
Department of Environmental Sciences, University of Siena, Italy.
Environ Pollut. 2019 Jun;249:610-619. doi: 10.1016/j.envpol.2019.03.047. Epub 2019 Mar 21.
Nowadays, the occurrence of a large volume of plastic litter in oceanic and coastal zones has increased concern about its impacts on marine organisms. The degradation of plastic polymers leads to the formation of smaller fragments at both micro and nano scale (<5 mm and <1 μm respectively). Nanoplastics (NPs), due to their smaller size and high specific surface area can establish colloidal interactions with marine microalgae, therefore potential toxicity can be led. . To assess this hypothesis, the aim of the present study is to examine the behaviour of polystyrene nanoparticles (PS NPs) of different sizes (50 and 100 nm) in marine water and their possible effects at different physiological and cellular levels in the marine diatom Phaeodactylum tricornutum. Different biomarkers and stress responses in P. tricornutum were analysed when organisms were exposed to environmentally relevant PS NPs concentrations between 0.1 and 50 mg L. Our results showed significant differences between controls and exposure microalgae, indicating toxicity. After 24 h, an increase in oxidative stress biomarkers, damage to the photosynthetic apparatus, DNA damage and depolarization of mitochondrial and cell membrane from 5 mg L were observed. Further after 72 h the inhibition of population growth and chlorophyll content were observed. Examining effects the effects related to PS NPs size, the smallest (50 nm) induced greater effects at 24 h while bigger PS NPs (100 nm) at72 h. This bigger particles (100 nm) showed more stability (in size distribution and spherical form) in the different culture media assayed, when compared with the rest of particles used. Strong adsorption and/or internalization of PS NPs was confirmed through changes in cell complexity and cell size as well as the fluorescence of 100 nm fluoresbrite PS NPs after washing cell surface.
如今，海洋和沿海地区大量塑料垃圾的出现引起了人们对其对海洋生物影响的关注。塑料聚合物的降解会导致微纳米尺度（分别<5mm 和<1μm）更小碎片的形成。由于纳米塑料（NPs）的尺寸较小且比表面积较高，它们可以与海洋微藻建立胶体相互作用，因此可能具有潜在毒性。为了评估这一假设，本研究的目的是研究不同尺寸（50nm 和 100nm）的聚苯乙烯纳米颗粒（PS NPs）在海水中的行为及其在海洋硅藻三角褐指藻不同生理和细胞水平上的可能影响。当生物暴露于环境相关的 PS NPs 浓度在 0.1 到 50mg/L 之间时，分析了三角褐指藻中的不同生物标志物和应激反应。与对照相比，暴露于微藻中的生物表现出显著差异，表明存在毒性。24 小时后，观察到氧化应激生物标志物增加、光合作用装置受损、DNA 损伤、线粒体和细胞膜去极化，这些现象在 5mg/L 时出现。进一步在 72 小时后观察到种群生长和叶绿素含量的抑制。检查与 PS NPs 尺寸相关的影响，发现最小尺寸（50nm）在 24 小时时引起更大的影响，而较大尺寸（100nm）在 72 小时时引起更大的影响。与使用的其他颗粒相比，这些较大的颗粒（100nm）在不同的培养介质中表现出更大的稳定性（在尺寸分布和球形方面）。通过改变细胞复杂性和细胞大小以及在洗涤细胞表面后 100nm 荧光微球 PS NPs 的荧光，证实了 PS NPs 的强烈吸附和/或内化。
