Shih Yu-Jen, Su Chia-Chi, Chen Chiu-Wen, Dong Cheng-Di, Liu Wen-Sheng, Huang C P
Department of Marine Environmental Engineering, National Kaohsiung Marine University, Kaohsiung 81157, Taiwan, ROC.
Asia-Pacific Biotech Developing Inc., Kaohsiung, Taiwan, ROC.
Chemosphere. 2016 Jul;154:109-117. doi: 10.1016/j.chemosphere.2016.03.061. Epub 2016 Apr 1.
The characteristics of nanoparticles (NPs) uptake may fundamentally alter physicochemical effects of engineered NPs on aquatic organisms, thereby yielding different ecotoxicology assessment results. The adsorption behavior of nano-TiO2 (P-25) on zebrafish embryos in Holtfreter's medium (pH 7.2, I ∼ 7.2 × 10(-2) M) and the presence of sodium alginate (100 mg/L) as dispersant was investigated. Zebrafish embryos (total 100) were exposed to nano-TiO2 at different concentrations (e.g., 0, 10, 20, 60, 120 mg/L) in batch-mode assay. The adsorption capacity of nano-TiO2 on fish eggs was determined by measuring the Ti concentration on the egg surface using ICP-OES analysis. Results showed that the adsorption capacity increased rapidly in the first hour, and then declined to reach equilibrium in 8 h. The adsorption characteristics was visualized as a three-step process of rapid initial layer formation, followed by break-up of aggregates and finally rearrangement of floc structures; the maximum adsorption capacity was the sum of an inner rigid layers of aggregates of 0.81-0.84 μg-TiO2/#-egg and an outer softly flocculated layers of 1.01 μg-TiO2/#-egg. The Gibbs free energy was 543.29-551.26 and 100.75 kJ/mol, respectively, for the inner-layer and the outer-layer aggregates. Adsorption capacity at 0.5-1.0 μg-TiO2/#-egg promoted egg hatching; but hatching was inhibited at higher adsorption capacity. Results clearly showed that the configuration of TiO2 aggregates could impact the hatching efficiency of zebrafish embryos.
纳米颗粒（NPs）的摄取特性可能会从根本上改变工程纳米颗粒对水生生物的物理化学效应，从而产生不同的生态毒理学评估结果。研究了纳米TiO₂（P-25）在霍尔特弗雷特培养基（pH 7.2，离子强度I ∼ 7.2 × 10⁻² M）中对斑马鱼胚胎的吸附行为以及海藻酸钠（100 mg/L）作为分散剂的存在情况。在分批模式试验中，将总共100个斑马鱼胚胎暴露于不同浓度（如0、10、20、60、120 mg/L）的纳米TiO₂中。通过使用电感耦合等离子体发射光谱（ICP-OES）分析测量卵表面的钛浓度，确定纳米TiO₂对鱼卵的吸附容量。结果表明，吸附容量在最初1小时内迅速增加，然后在8小时内下降至平衡。吸附特性可直观化为一个三步过程：首先快速形成初始层，随后聚集体解体，最后絮凝结构重新排列；最大吸附容量是由0.81 - 0.84 μg-TiO₂/个卵的内部刚性聚集体层和1.01 μg-TiO₂/个卵的外部柔软絮凝层组成。内层和外层聚集体的吉布斯自由能分别为543.29 - 551.26和100.75 kJ/mol。吸附容量为0.5 - 1.0 μg-TiO₂/个卵时促进卵孵化；但吸附容量较高时孵化受到抑制。结果清楚地表明，TiO₂聚集体的形态会影响斑马鱼胚胎的孵化效率。
