Department of Electrical Engineering and Computer Science, University of Missouri-Columbia, MO, USA.
Department of Veterinary Pathology, University of Missouri-Columbia, MO, USA.
Anal Chim Acta. 2023 Aug 1;1267:341226. doi: 10.1016/j.aca.2023.341226. Epub 2023 May 11.
-In this paper, we investigate a microfluidic based sensing device for cell membrane permeability measurements in real time with applications in rapid assessment of red blood cell (RBC) quality at the individual cell level. The microfluidic chip was designed with unique abilities to line up the RBCs in the centerline of the microchannel using positive dielectrophoresis (p-DEP) forces, rapid mixing of RBCs with various media (e.g. containing permeating or nonpermeating solutes) injected from different inlets to achieve high mixing efficiency. The chip detects the impedance values of the RBCs within 0.19 s from the start of mixing with other media, at ten electrodes along the length of the channel and enables time series measurements of volume change of individual cell caused by cell osmosis in anisosmotic fluids over a 0.8 s postmixing timespan. This technique enables estimating water permeability of individual cell accurately. Here we first present confirmation of a linear voltage-diameter relationship in polystyrene bead standards. Next, we show that under equilibrium conditions, the voltage-volume relationship in rat red blood cells (RBCs) is linear, corresponding to previously published Boyle van 't Hoff plots. Using rat cells as a model for human, we present the first measurement of water permeability in individual red blood cells and confirm that these data align with previously published population level values for human RBC. Finally, we present preliminary evidence for possible application of our device to identify individual RBCs infected with Plasmodium falciparum malaria parasites. Future developments using this device will address the use of whole blood with non-homogenous cell populations, a task currently performed by clinical Coulter counters.
在本文中，我们研究了一种基于微流控的传感设备，用于实时测量细胞膜通透性，可应用于快速评估个体细胞水平的红细胞（RBC）质量。该微流控芯片具有独特的能力，可以使用正介电泳（p-DEP）力将 RBC 排列在微通道的中心线内，并且可以从不同的入口快速混合 RBC 与各种介质（例如含有渗透或非渗透溶质的介质），以实现高效率的混合。该芯片在与其他介质混合的 0.19 s 内从开始混合开始，在沿着通道长度的十个电极上检测 RBC 的阻抗值，并在混合后 0.8 s 的时间内对各个细胞由于细胞渗透引起的体积变化进行时间序列测量。该技术可以准确估计各个细胞的水通透性。在这里，我们首先证明了聚苯乙烯珠标准品中存在线性电压-直径关系。接下来，我们表明在平衡条件下，大鼠红细胞（RBC）中的电压-体积关系是线性的，与以前发表的 Boyle van 't Hoff 图相对应。使用大鼠细胞作为人类模型，我们首次测量了个体红细胞中的水通透性，并证实这些数据与以前发表的人类 RBC 群体水平值一致。最后，我们初步证明了我们的设备可能用于识别感染恶性疟原虫的个体 RBC。使用该设备的未来发展将解决使用具有非均匀细胞群体的全血的任务，这是临床库尔特计数器目前执行的任务。
