从金属纳米颗粒的理化性质以及生物吸收动力学角度探究金属纳米颗粒对水生生物的毒性(英文)

Significance of physicochemical and uptake kinetics in controlling the toxicity of metallic nanomaterials to aquatic organisms

研究目的:研究金属纳米颗粒在进入水体后的一系列动力学过程对金属纳米颗粒的生物可利用性和毒性可能产生的影响。研究方法:针对在毒性测试中金属纳米颗粒的解析现象,选取三种常见的金属纳米颗粒(纳米氧化锌、纳米银和纳米二氧化钛),总结了它们在毒性测试中的解析动力学、溶解性以及毒性。同时,综合水生生物对金属纳米颗粒以及离子的吸收动力学,利用动态模型进行模拟,阐述解离的离子在生物对金属纳米颗粒吸收中的贡献。重要结论:在评价金属纳米颗粒和解析离子对水生生物的生物利用度和毒性的测试过程中,需要综合考虑金属纳米颗粒的理化性质以及生物吸收动力学过程。

With the extensive applications of metallic-based nanomaterials （MNs）, concerns are growing of their potential impact on aquatic organisms. Unlike traditional metal pollutants, MNs have different surface properties and compositions, which may modify their impact on aquatic environments as well as their bioavailability to aquatic organisms. Kinetic processes of MNs, such as dissolution, stabilization, aggregation, and sedimentation, are important in determining their bioavailability and subse-quent toxicity to aquatic organisms. Among all of the physicochemical kinetics, the dissolution of MNs attracts the most attention, due to their potential toxicity generated by dissolved ions. This review summarizes the dissolution behavior of three common MNs, i.e., ZnO nanoparticles （ZnO-NPs）, Ag nanoparticles （Ag-NPs）, and TiO2 nanoparticles （TiO2-NPs）, in toxicological studies. A kinetic model was developed to evaluate the contribution of dissolved ion on the total MN accumulation. Finally, toxicological data of the MNs to algae, zooplankton, and fish are summarized and interpreted based on their kinetics. Different dissolution rates were observed for ZnO-NPs, Ag-NPs, and TiO2-NPs, and their solubility also varied during different toxicological studies, leading to a variable but increasing waterborne ion concentration during exposure. The bioavailability of these MNs and corresponding ions also varied for different aquatic organisms （e.g., algae, zooplankton, and fish）. Specifically, the MNs appeared to be more bioavailable to daphnids, rendering a minor contribution of ion during short-term exposure. Generally, dissolved ion contributed partially to toxicity of ZnO-NPs and Ag-NPs, while the toxicity of TiO2-NPs was mainly due to the generated reactive oxygen species （ROS）. Additionally, the role of dissolved ion in both MN bioaccumulation and toxicity intensified during chronic ex-posure as a result of dissolution, thus it is critical to monitor the dissolution of MNs in toxicological studies. This review empha-sizes the importance of integrating physicochemical kinetics and uptake kinetics in evaluating the bioavailability and toxicity of both MNs and dissolved ions.