Scientific and Educational Center for Environmental Science and Biotechnology, Derzhavin Tambov State University, 392020 Tambov, Russia.
Department of Functional Nanosystems and High-Temperature Materials, National University of Science and Technology "MISIS", 119991 Moscow, Russia.
Int J Mol Sci. 2024 Aug 23;25(17):9167. doi: 10.3390/ijms25179167.
The removal of pollutants, including heavy metals, from the aquatic environment is an urgent problem worldwide. Actively developing nanotechnology areas is becoming increasingly important for solving problems in the field of the remediation of aquatic ecosystems. In particular, methods for removing pollutants using nanoparticles (NPs) are proposed, which raises the question of the effect of a combination of NPs and heavy metals on living organisms. In this work, we investigated the role of CuO-NPs in changing the toxicity of Cd and Pb salts, as well as the bioaccumulation of these elements in a culture of the microalga . It was found that CuO-NPs at concentrations of 10, 100, and 1000 µg L had no effect on the viability of microalgae cells. On the 14th day of the experiment, Cd at a concentration of 1 mg L reduced the viability index by 30% and, when combined with CuO-NPs, by 25%, i.e., CuO-NPs slightly reduced the toxic effect of Cd. At the same time, in this experiment, when CuO-NPs and Cd were used together, the level of oxidative stress increased, including on the first day in mixtures with 1 mg L Cd. Under the influence of Pb, the cell viability index decreased by 70% by the end of the experiment, regardless of the metal concentration. The presence of CuO-NPs slightly reduced the toxicity of Pb in terms of viability and reactive oxygen species (ROS). At the same time, unlike Cd, Pb without NPs caused ROS production on the first day, whereas the addition of CuO-NPs completely detoxified Pb at the beginning and had a dose-dependent effect on mixtures at the end of the experiment. Also, the introduction of CuO-NPs slightly reduced the negative effect of Pb on pigment synthesis. As a molecular mechanism of the observed effects, we prioritized the provocation of oxidative stress by nanoparticles and related gene expression and biochemical reactions of algae cells. Analysis of the effect of CuO-NPs on the Cd and Pb content in microalgae cells showed increased accumulation of heavy metals. Thus, when algae were cultured in an environment with Cd and CuO-NPs, the Cd content per cell increased 4.2 times compared to the variant where cells were cultured only with Cd. In the case of Pb, the increase in its content per one cell increased 6.2 times when microalgae were cultured in an environment containing CuO-NPs. Thus, we found that CuO-NPs reduce the toxic effects of Cd and Pb, as well as significantly enhance the bioaccumulation of these toxic elements in the cells of microalgae. The results obtained can form the basis of technology for the nanobioremediation of aquatic ecosystems from heavy metals using microalgae.
从水生环境中去除污染物，包括重金属，是全世界的一个紧迫问题。积极开发纳米技术领域对于解决水生生态系统修复领域的问题变得越来越重要。特别是，提出了使用纳米颗粒（NPs）去除污染物的方法，这就提出了 NPs 和重金属对生物体的综合影响的问题。在这项工作中，我们研究了 CuO-NPs 在改变 Cd 和 Pb 盐的毒性以及这些元素在微藻培养物中的生物积累方面的作用。结果发现，浓度为 10、100 和 1000μg/L 的 CuO-NPs 对微藻细胞的存活率没有影响。在实验的第 14 天，浓度为 1mg/L 的 Cd 使存活率指数降低了 30%，而与 CuO-NPs 结合时，降低了 25%，即 CuO-NPs 略微降低了 Cd 的毒性作用。同时，在这项实验中，当 CuO-NPs 和 Cd 一起使用时，氧化应激水平增加，包括在含有 1mg/L Cd 的混合物中第 1 天。在 Pb 的影响下，到实验结束时，细胞存活率指数降低了 70%，而与金属浓度无关。CuO-NPs 的存在略微降低了 Pb 在存活率和活性氧物质（ROS）方面的毒性。同时，与 Cd 不同，没有 NPs 的 Pb 在第一天就产生了 ROS，而添加 CuO-NPs 则在开始时完全使 Pb 解毒，并在实验结束时对混合物产生剂量依赖性影响。此外，CuO-NPs 的引入略微降低了 Pb 对色素合成的负面影响。作为观察到的效应的分子机制，我们优先考虑纳米颗粒引起的氧化应激以及藻类细胞的相关基因表达和生化反应。分析 CuO-NPs 对微藻细胞中 Cd 和 Pb 含量的影响表明，重金属的积累增加。因此，当藻类在含有 Cd 和 CuO-NPs 的环境中培养时，与仅在 Cd 存在的情况下培养的细胞相比，每个细胞中的 Cd 含量增加了 4.2 倍。对于 Pb，当微藻在含有 CuO-NPs 的环境中培养时，每个细胞中 Pb 含量增加了 6.2 倍。因此，我们发现 CuO-NPs 降低了 Cd 和 Pb 的毒性作用，并且显著增强了这些有毒元素在微藻细胞中的生物积累。所获得的结果可以为使用微藻从重金属中进行水生生态系统的纳米生物修复技术提供基础。
