Distribution of Fullerene Nanomaterials between Water and Model Biological Membranes
Distribution of Fullerene Nanomaterials between Water and Model Biological Membranes
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DOI：
10.1021/la2017837
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发表时间：
2011-10-04
期刊：
影响因子：
3.9
通讯作者：
Posner, Jonathan D.
中科院分区：
文献类型：
--
作者：
Hou, Wen-Che;Moghadam, Babak Yaghoubi;Posner, Jonathan D.
生物膜是细胞与污染物接触的重要界面之一。许多极性和疏水性化学物质可以在这些膜内积聚。因此，人工生物膜是复杂生物体评估工程纳米材料生物累积潜力的有吸引力的替代品。据我们所知，这项工作提出了第一个定量研究的富勒烯ENMs之间的脂质双层，用作模型biologica膜，和水的分布。我们评估了水溶液富勒烯聚集体（nC（60））和富勒醇（C-60（ONa）（x）（OH）（y），x + y = 24）的脂双层-水缔合系数（K-lipw）。动力学研究表明，富勒醇比nC（60）更快地达到表观平衡（2小时对>9小时）。nC 60和富勒醇的分布行为可用非线性等温线描述。nC（60）和富勒醇的脂质双层水分布是pH依赖性的，随着pH从8.6（天然水pH）降低到3（生理相关pH的低端），脂质双层中的积累系统地增加。这种pH依赖性随ENM的ζ电位而变化，并导致与先前观察到的可电离有机污染物的脂质双层水分布行为相似的模式。在给定pH下，nC（60）的K-lipw值大于富勒醇的K-lipw值，表明nC（60）与脂质双层相互作用的倾向更大。例如，在pH 7.4和10 mg/L的水溶液浓度下，nC（60）（log K-lipw = 2.99）的K-lipw是富勒醇（log K-lipw = 2.45）的3.5倍。与现有水生生物生物累积性研究的比较表明，脂双层水分布是评估环境纳米物质生物累积潜力的一种潜在方法。
Biological membranes are one of the important interfaces between cells and pollutants. Many polar and hydrophobic chemicals can accumulate within these membranes. For this reason, artificial biological membranes are appealing surrogates to complex organisms for assessing the bioaccumulation potential of engineered nanomaterials (ENMs). To our knowledge, this work presents the first quantitative study on the distribution of fullerene ENMs between lipid bilayers, used as model biologica membranes, and water. We evaluated the lipid bilayer-water association coefficients (K-lipw) of aqueous fullerene aggregates (nC(60)) and fullerol (C-60(ONa)(x)(OH)(y), x + y = 24). Kinetic studies indicated that fullerol reached apparent equilibrium more rapidly than nC(60) (2 h versus >9 h). Nonlinear isotherms can describe the distribution behavior of nC60 and fullerol. The lipid bilayer water distributions of both nC(60) and fullerol were pH-dependent with the accumulation in lipid bilayers increasing systematically as the pH decreased from 8.6 (natural water pH) to 3 (the low end of physiologically relevant pH). This pH dependency varies with the zeta potentials of the ENMs and leads to patterns similar to those previously observed for the lipid bilayer water distribution behavior of ionizable organic pollutants. The K-lipw value for nC(60) was larger than that of fullerol at a given pH, indicating a greater propensity for nC(60) to interact with lipid bilayers. For example, at pH 7.4 and an aqueous concentration of 10 mg/L, K-lipw, was 3.5 times greater for nC(60) (log K-lipw = 2.99) relative to fullerol (log K-lipw = 2.45). Comparisons with existing aquatic organism bioaccumulation studies suggested that the lipid bilayer water distribution is a potential method for assessing the bioaccumulation potentials of ENMs.