Impedance-based cell monitoring: barrier properties and beyond.
Impedance-based cell monitoring: barrier properties and beyond.
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DOI：
10.1186/2045-8118-10-5
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发表时间：
2013-01-10
影响因子：
7.3
通讯作者：
Galla HJ
中科院分区：
文献类型：
--
作者：
Benson K;Cramer S;Galla HJ
在多细胞生物中，上皮细胞和内皮细胞在不同化学成分的组织区室之间形成选择性渗透界面。连接相邻细胞的紧密连接，控制分子穿过屏障，此外，促进主动转运过程。细胞屏障不是静态的，而是可以通过暴露于特定的外部刺激来故意调节。目前已有代表人体基本吸收屏障的体外模型，从而可以研究控制渗透性以及穿过这些屏障的转运过程的参数。独立的屏障形成细胞的起源，需要技术来量化其屏障的完整性。一种简单的测定是测量具有不同分子量的给定亲水性底物（如蔗糖或葡聚糖）的渗透性。然而，这种技术是耗时和劳动密集型的。此外，需要放射性或荧光标记的底物以允许容易的分析检测。最后，如果研究运输过程，标准渗透物可能会干扰所研究的运输过程，甚至可能本身改变屏障的完整性。因此，需要独立的、非侵入性的技术来在实验期间连续地量化屏障完整性。这些技术是可用的，并且主要基于在多孔膜上生长的屏障形成细胞的跨内皮或跨上皮电阻（TEER）的测量。使用两组电极的简单装置（所谓的伏特计）被广泛使用。此外，一种称为阻抗谱的易于使用的物理技术允许对TEER和电容进行连续分析，从而提供有关在渗透膜上生长的细胞的屏障特性的额外信息。该技术可用作屏障形成细胞的质量控制。另一种基于阻抗的方法要求细胞直接在固体微结构电极上生长。在这里，我们将讨论不同技术的物理背景;优点，缺点和应用将被仔细检查。其目的是让读者全面了解应用的范围和限制，主要集中在内皮细胞上。
In multicellular organisms epithelial and endothelial cells form selective permeable interfaces between tissue compartments of different chemical compositions. Tight junctions which connect adjacent cells, control the passage of molecules across the barrier and, in addition, facilitate active transport processes. The cellular barriers are not static but can be deliberately modulated by exposure to specific external stimuli. In vitro models representing the essential absorption barriers of the body are nowadays available, thus allowing investigation of the parameters that control permeability as well as transport processes across those barriers. Independent of the origin of the barrier forming cells, techniques are needed to quantify their barrier integrity. One simple assay is to measure the permeability for given hydrophilic substrates possessing different molecular weights like sucrose or dextrans. However, this technique is time-consuming and labor-intensive. Moreover, radioactive or fluorescently-labeled substrates are needed to allow easy analytical detection. Finally, if transport processes are investigated, the standard permeant may interfere with the transport process under investigation or might even alter the barrier integrity by itself. Thus, independent, non-invasive techniques are needed to quantify the barrier integrity continuously during the experiment. Such techniques are available and are mainly based on the measurement of the transendothelial or transepithelial electrical resistance (TEER) of barrier forming cells grown on porous membranes. Simple devices using two sets of electrodes (so-called Voltohmeters) are widely used. In addition, an easy-to-use physical technique called impedance spectroscopy allows the continuous analysis of both the TEER and the electrical capacitance giving additional information about the barrier properties of cells grown on permeable membranes. This technique is useful as a quality control for barrier forming cells. Another impedance-based approach requires cells to be grown directly on solid, micro-structured electrodes. Here, we will discuss the physical background of the different techniques; advantages, disadvantages, and applications will be scrutinized. The aim is to give the reader a comprehensive understanding concerning the range and limits of the application, mainly focusing on endothelial cells.