KTH Royal Institute of Technology, Department of Chemistry, Division of Surface and Corrosion Science, Drottning Kristinas vag 51, SE-100 44 Stockholm, Sweden; National University of Science and Technology "MISiS", Research Center of Engineering Ceramic Nanomaterials, Moscow, Russia.
University of Gothenburg, Department of Biological and Environmental Sciences, Gothenburg, Sweden.
NanoImpact. 2022 Jan;25:100386. doi: 10.1016/j.impact.2022.100386. Epub 2022 Jan 31.
Increased use and production of engineered nanoparticles (NPs) lead to an elevated risk of their diffuse dispersion into the aquatic environment and increased concern on unknown effects induced by their release into the aquatic ecosystem. An improved understanding of the environmental transformation processes of NPs of various surface characteristics is hence imperative for risk assessment and management. This study presents results on effects of natural organic matter (NOM) on the environmental transformation and dissolution of metal and metal oxide NPs of different surface and solubility properties in synthetic freshwater (FW) with and without NOM. Adsorption of NOM was evident on most of the studied NPs, except Sb and SbO, which resulted in the formation of negatively charged colloids of higher stability and smaller size distribution compared with the same NPs in FW only. The dissolution rate of the NPs in the presence of NOM correlated with the strength of interactions between the carboxylate group of NOM and the particle surface, and resulted in either no (Mn, Sb, ZnO NPs), increased (Co, Sn NPs) and decreased (Ni, NiO, SbO, YO NPs) levels of dissolution. One type of metal NP from each group (Mn, Ni, Sn) were investigated to assess whether observed differences in adsorption of NOM and dissolution would influence their ecotoxic potency. The results showed Mn, Ni, and Sn NPs to generate intracellular reactive oxygen species (ROS) in a time and dose-dependent manner. The extent of ROS generation in FW was similar for both Mn and Ni NPs but higher for Sn NPs. These findings are possibly related to interactions and infiltration of the NPs with the cells, which lead to redox imbalances which could induce oxidative stress and cell damage. At the same time, the presence of NOM generally reduced the intracellular ROS generation by 20-40% for the investigated NPs and also reduced cytotoxicity of Sn NPs, which can be attributed to the stronger interaction of carboxylate groups of NOM with the surface of the NPs.
随着工程纳米粒子（NPs）的使用和产量的增加，它们弥散分散到水生环境中的风险增加，并且人们越来越关注它们释放到水生生态系统中所带来的未知影响。因此，为了进行风险评估和管理，迫切需要更好地了解具有各种表面特性的 NPs 的环境转化过程。本研究旨在探讨天然有机物（NOM）对不同表面特性和溶解度的金属和金属氧化物 NPs 在合成淡水（FW）中的环境转化和溶解的影响，以及 NOM 的存在对这些过程的影响。结果表明，除了 Sb 和 SbO 之外，大多数研究中的 NPs 都明显吸附了 NOM，这导致了与仅在 FW 中相同 NPs 相比具有更高稳定性和更小粒径分布的带负电荷胶体的形成。在 NOM 存在下，NPs 的溶解速率与 NOM 中的羧酸盐基团与粒子表面之间相互作用的强度相关，并且导致溶解水平要么没有（Mn、Sb、ZnO NPs），要么增加（Co、Sn NPs），要么减少（Ni、NiO、SbO、YO NPs）。从每个组中选择一种金属 NP（Mn、Ni、Sn）进行研究，以评估吸附 NOM 和溶解的差异是否会影响它们的生态毒性。结果表明，Mn、Ni 和 Sn NPs 能够以时间和剂量依赖的方式产生细胞内活性氧物质（ROS）。在 FW 中，Mn 和 Ni NPs 产生 ROS 的程度相似，但 Sn NPs 产生的程度更高。这些发现可能与 NPs 与细胞的相互作用和渗透有关，这导致了氧化还原失衡，从而可能引发氧化应激和细胞损伤。同时，NOM 的存在通常会降低所研究的 NPs 细胞内 ROS 生成 20-40%，并降低 Sn NPs 的细胞毒性，这可归因于 NOM 中的羧酸盐基团与 NPs 表面的更强相互作用。
