von Moos Nadia, Maillard Luca, Slaveykova Vera I
Environmental Biogeochemistry and Ecotoxicology, Earth and Environmental Science Section, Institute F.-A. Forel, University of Geneva, 10, Route de Suisse, CH-1290 Versoix, Switzerland.
Environmental Biogeochemistry and Ecotoxicology, Earth and Environmental Science Section, Institute F.-A. Forel, University of Geneva, 10, Route de Suisse, CH-1290 Versoix, Switzerland.
Aquat Toxicol. 2015 Apr;161:267-75. doi: 10.1016/j.aquatox.2015.02.010. Epub 2015 Feb 20.
Though nano-CuO has been classified as toxic toward aquatic microorganisms and its use in various applications is expected to increase in near future, its ecotoxicity is currently poorly understood. The aim of this study was to investigate the mechanisms of nano-CuO toxicity based on the paradigm of oxidative stress, the dynamics of response over 24h, and the modulating effect of exposure conditions on toxicity and responses. To this end, the model microalga Chlamydomonas reinhardtii was exposed to 10mgL(-1) nano-CuO in five different exposure media, including two different growth media, two Good's buffers, and natural lake water. The measured endpoints included cell growth, morphological aspect, chlorophyll autofluorescence, oxidative stress, and membrane permeabilization. The results suggest that agglomerated nano-CuO is toxic and that exposure media are decisive in whether or not particles or free Cu ions are the main mediators of toxicity. A significant particle effect was only observed in the Good's buffer 3-(N-morpholino) propanesulfonic acid. However, nano-CuO particles especially influenced the dynamics of response early in exposure, between 0h and 5h, suggesting that an adaptation to particle stress may occur or that particles modify the bioavailability of the free Cu ions in early exposure.
尽管纳米氧化铜已被归类为对水生微生物有毒，且预计其在各种应用中的使用在不久的将来会增加，但其生态毒性目前仍知之甚少。本研究的目的是基于氧化应激范式、24小时内的反应动态以及暴露条件对毒性和反应的调节作用，研究纳米氧化铜毒性的机制。为此，将模式微藻莱茵衣藻暴露于五种不同暴露介质中的10mgL(-1)纳米氧化铜中，包括两种不同的生长介质、两种Good's缓冲液和天然湖水。所测量的终点包括细胞生长、形态、叶绿素自发荧光、氧化应激和膜通透性。结果表明，团聚的纳米氧化铜具有毒性，且暴露介质对于颗粒或游离铜离子是否是毒性的主要介质起着决定性作用。仅在Good's缓冲液3-(N-吗啉代)丙磺酸中观察到显著的颗粒效应。然而，纳米氧化铜颗粒尤其在暴露早期（0小时至5小时之间）影响反应动态，这表明可能会出现对颗粒应激的适应，或者颗粒在早期暴露中改变了游离铜离子的生物利用度。
