Quantitative characterization of nanoparticle agglomeration within biological media
Quantitative characterization of nanoparticle agglomeration within biological media
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DOI：
10.1007/s11051-012-0977-3
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发表时间：
2012-07-01
影响因子：
2.5
通讯作者：
Brown, Andy
中科院分区：
文献类型：
--
作者：
Hondow, Nicole;Brydson, Rik;Brown, Andy
定量分析纳米颗粒在生物介质中的分散状态对于理解细胞摄取以及扩散、沉积和内吞作用在确定纳米颗粒剂量中的作用至关重要。采用透射电镜（TEM）和动态光散射（DLS）技术分析了聚合物包被CdTe/ZnS量子点在含胎牛血清和不含胎牛血清的水和细胞生长培养基中的分散情况。通过将印迹溶液浸入乙烷中冷冻制备的样品的TEM表征对量子点的分散状态敏感，并且即使在DLS失败的血清蛋白存在的情况下也可以测量团聚体大小分布。此外，透射电镜显示，与仅在水中相比，分散在生物介质和血清中的量子点每团块的堆积分数减少，突出了介质、血清蛋白和量子点之间相互作用的影响。通过透射电镜鉴定细胞生长培养基和血清中量子点和量子点团块的非均匀分布将与先前报道的量子点分散的体外细胞摄取的光学计量相关联。在本文中，我们提出了TEM和DLS的比较研究，并表明骤降冻结TEM提供了纳米颗粒团聚状态的可靠评估。
Quantitative analysis of nanoparticle dispersion state within biological media is essential to understanding cellular uptake and the roles of diffusion, sedimentation, and endocytosis in determining nanoparticle dose. The dispersion of polymer-coated CdTe/ZnS quantum dots in water and cell growth medium with and without fetal bovine serum was analyzed by transmission electron microscopy (TEM) and dynamic light scattering (DLS) techniques. Characterization by TEM of samples prepared by plunge freezing the blotted solutions into liquid ethane was sensitive to the dispersion state of the quantum dots and enabled measurement of agglomerate size distributions even in the presence of serum proteins where DLS failed. In addition, TEM showed a reduced packing fraction of quantum dots per agglomerate when dispersed in biological media and serum compared to just water, highlighting the effect of interactions between the media, serum proteins, and the quantum dots. The identification of a heterogeneous distribution of quantum dots and quantum dot agglomerates in cell growth medium and serum by TEM will enable correlation with the previously reported optical metrology of in vitro cellular uptake of this quantum dot dispersion. In this paper, we present a comparative study of TEM and DLS and show that plunge-freeze TEM provides a robust assessment of nanoparticle agglomeration state.