How a cell senses, responds, and moves toward, or away from an external cue is central to many biological and medical phenomena including morphogenesis, immune response, and cancer metastasis. Many eukaryotic cells have internal sensory mechanisms that allow them to sense these cues, often in the form of gradients of chemoattractant, voltage, or mechanical stress, and bias their motion in a specific direction. In this study, a new method for using microfluidics to study the electrotactic migration of cells is presented. Electrotaxis (also known as galvanotaxis) is the phenomenon by which cells bias their motion directionally in response to an externally applied electrical field. In this work, we present a new flow-based, salt bridge-free microfluidic device for imaging and quantifying cell motility and intracellular ion activity during electrotaxis. To eliminate salt bridges, we used a low nanoliter flow rate to slowly drive Faradaic waste products away from and out of the electrotaxis zone. This cell migration zone consisted of an array of fluidic confinement channels approximately 2 μm in thickness. This confined height served to insulate the migrating cells from the electric field at the top and bottom of the cell, such that only the two-dimensional perimeter of the cells interacted with the electrical source. We demonstrate the ability to quantify the electrotactic velocity of migrating Dictyostelium discoideum cells and show how this confined design facilitates the imaging and quantification of the ion activity of electrotaxing cells. Finally, by spatially imaging the calcium concentration within these cells, we demonstrate that intracellular calcium preferentially translocates to the leading edge of migrating Dictyostelium cells during electrotaxis but does not exhibit this behavior during migration by chemotaxis in a gradient of cyclic adenosine 3',5'-monophosphate or when cells freely migrate in the absence of an external cue.

中文翻译：

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一种基于流的微流控设备，用于在细胞电纺过程中空间量化细胞内钙离子的活性。

细胞如何感测，响应和朝向或远离外部提示移动是许多生物学和医学现象（包括形态发生，免疫反应和癌症转移）的关键。许多真核细胞具有内部感觉机制，使它们能够以化学引诱剂，电压或机械应力的梯度形式来感知这些线索，并将其运动偏向特定的方向。在这项研究中，提出了一种使用微流控技术研究细胞电迁移的新方法。电轴作用（也称为通电）是细胞响应于外部施加的电场而定向偏移其运动的现象。在这项工作中，我们提出了一种基于流程的新方法，无盐桥微流控设备，用于在电出租车期间成像和量化细胞运动性和细胞内离子活性。为了消除盐桥，我们使用了低纳升的流速来缓慢地将法拉第废品驱逐出和离开电出租车区。该细胞迁移区由一系列厚度约2μm的流体限制通道组成。该限制的高度用于使迁移的细胞与细胞顶部和底部的电场隔离，从而仅细胞的二维周边与电源相互作用。我们展示了量化迁移盘基网柄菌细胞的电速的能力，并展示了这种有限的设计如何促进成像和量化电税细胞的离子活性。最后，