Department of Imaging Physics Research, The University of Texas M.D. Anderson Cancer Center Unit 951, 1515 Holcombe Boulevard, Houston, TX 77030, USA.
Cancers (Basel). 2014 Mar 12;6(1):545-79. doi: 10.3390/cancers6010545.
Dielectrophoresis (DEP) is an electrokinetic method that allows intrinsic dielectric properties of suspended cells to be exploited for discrimination and separation. It has emerged as a promising method for isolating circulation tumor cells (CTCs) from blood. DEP-isolation of CTCs is independent of cell surface markers. Furthermore, isolated CTCs are viable and can be maintained in culture, suggesting that DEP methods should be more generally applicable than antibody-based approaches. The aim of this article is to review and synthesize for both oncologists and biomedical engineers interested in CTC isolation the pertinent characteristics of DEP and CTCs. The aim is to promote an understanding of the factors involved in realizing DEP-based instruments having both sufficient discrimination and throughput to allow routine analysis of CTCs in clinical practice. The article brings together: (a) the principles of DEP; (b) the biological basis for the dielectric differences between CTCs and blood cells; (c) why such differences are expected to be present for all types of tumors; and (d) instrumentation requirements to process 10 mL blood specimens in less than 1 h to enable routine clinical analysis. The force equilibrium method of dielectrophoretic field-flow fractionation (DEP-FFF) is shown to offer higher discrimination and throughput than earlier DEP trapping methods and to be applicable to clinical studies.
介电泳（DEP）是一种电动方法，可利用悬浮细胞的固有介电特性进行区分和分离。它已成为从血液中分离循环肿瘤细胞（CTC）的一种很有前途的方法。DEP 分离 CTC 不依赖于细胞表面标志物。此外，分离出的 CTC 是有活力的，可以在培养中维持，这表明 DEP 方法应该比基于抗体的方法更具有普遍性。本文的目的是为对 CTC 分离感兴趣的肿瘤学家和生物医学工程师综述和综合介电泳和 CTC 的相关特性。目的是促进对实现基于 DEP 的仪器的相关因素的理解，该仪器具有足够的区分度和吞吐量，从而能够在临床实践中常规分析 CTC。本文汇集了：（a）DEP 的原理；（b）CTC 和血细胞之间介电差异的生物学基础；（c）为什么所有类型的肿瘤都可能存在这种差异；以及（d）处理 10 mL 血液样本的仪器要求，以在不到 1 小时的时间内进行常规临床分析。介电泳场流分离（DEP-FFF）的力平衡法被证明比早期的 DEP 捕获方法具有更高的区分度和吞吐量，并且适用于临床研究。
