Ye Nan, Wang Zhuang, Wang Se, Fang Hao, Wang Degao
a School of Environmental Science and Engineering, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Nanjing University of Information Science and Technology , Nanjing , PR China.
b School of Environmental Science and Technology, Dalian Maritime University , Dalian , PR China.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2018 Jun 7;53(7):651-658. doi: 10.1080/10934529.2018.1438814. Epub 2018 Feb 22.
This study investigated the impact of dissolved organic matters (DOM) on the ecological toxicity of aluminum oxide nanoparticles (AlONPs) at a relatively low exposure concentration (1 mg L). The unicellular green alga Scenedesmus obliquus was exposed to AlONP suspensions in the presence of DOM (fulvic acid) at various concentrations (1, 10, and 40 mg L). The results show that the presence of DOM elevated the growth inhibition toxicity of AlONPs towards S. obliquus in a dose-dependent manner. Moreover, the combination of DOM at 40 mg L and AlONPs resulted in a synergistic effect. The relative contribution of Al-ions released from AlONPs to toxicity was lower than 5%, indicating that the presence of the particles instead of the dissolved ions in the suspensions was the major toxicity sources, regardless of the presence of DOM. Furthermore, DOM at 10 and 40 mg L and AlONPs synergistically induced the upregulation of intercellular reactive oxygen species levels and superoxide dismutase activities. Analysis of the plasma malondialdehyde concentrations and the observation of superficial structures of S. obliquus indicated that the mixtures of DOM and AlONPs showed no significant effect on membrane lipid peroxidation damage. In addition, the presence of both DOM and AlONPs contributed to an enhancement in both the mitochondrial membrane potential and the cell membrane permeability (CMP) in S. obliquus. In particular, AlONPs in the presence of 10 and 40 mg L DOM caused a greater increase in CMP compared to AlONPs and DOM alone treatments. In conclusion, these findings suggest that DOM at high concentrations and AlONPs synergistically interrupted cell membrane functions and triggered subsequent growth inhibition toxicity.
本研究调查了在相对低暴露浓度（1毫克/升）下溶解有机物（DOM）对氧化铝纳米颗粒（AlONPs）生态毒性的影响。将单细胞绿藻斜生栅藻暴露于含有不同浓度（1、10和40毫克/升）DOM（富里酸）的AlONP悬浮液中。结果表明，DOM的存在以剂量依赖的方式提高了AlONPs对斜生栅藻的生长抑制毒性。此外，40毫克/升的DOM与AlONPs的组合产生了协同效应。AlONPs释放的铝离子对毒性的相对贡献低于5%，这表明悬浮液中颗粒而非溶解离子的存在是主要的毒性来源，无论DOM是否存在。此外，10和40毫克/升的DOM与AlONPs协同诱导细胞内活性氧水平和超氧化物歧化酶活性上调。对斜生栅藻血浆丙二醛浓度的分析以及对其表面结构的观察表明，DOM和AlONPs的混合物对膜脂过氧化损伤没有显著影响。此外，DOM和AlONPs的存在都导致斜生栅藻线粒体膜电位和细胞膜通透性（CMP）增强。特别是，与单独处理AlONPs和DOM相比，在10和40毫克/升DOM存在下的AlONPs导致CMP有更大的增加。总之，这些发现表明高浓度的DOM和AlONPs协同干扰细胞膜功能并引发随后的生长抑制毒性。
