Aghaamoo Mohammad, Cardenas-Benitez Braulio, Lee Abraham P
Department of Biomedical Engineering, University of California Irvine, Irvine, CA 92697, USA.
Center for Advanced Design & Manufacturing of Integrated Microfluidics (CADMIM), University of California Irvine, Irvine, CA 92697, USA.
Micromachines (Basel). 2023 Sep 22;14(10):1813. doi: 10.3390/mi14101813.
Dielectrophoresis (DEP) is a powerful tool for label-free sorting of cells, even those with subtle differences in morphological and dielectric properties. Nevertheless, a major limitation is that most existing DEP techniques can efficiently sort cells only at low throughputs (<1 mL h). Here, we demonstrate that the integration of a three-dimensional (3D) coupled hydrodynamic-DEP cell pre-focusing module upstream of the main DEP sorting region enables cell sorting with a 10-fold increase in throughput compared to conventional DEP approaches. To better understand the key principles and requirements for high-throughput cell separation, we present a comprehensive theoretical model to study the scaling of hydrodynamic and electrostatic forces on cells at high flow rate regimes. Based on the model, we show that the critical cell-to-electrode distance needs to be ≤10 µm for efficient cell sorting in our proposed microfluidic platform, especially at flow rates ≥ 1 mL h. Based on those findings, a computational fluid dynamics model and particle tracking analysis were developed to find optimum operation parameters (e.g., flow rate ratios and electric fields) of the coupled hydrodynamic-DEP 3D focusing module. Using these optimum parameters, we experimentally demonstrate live/dead K562 cell sorting at rates as high as 10 mL h (>150,000 cells min) with 90% separation purity, 85% cell recovery, and no negative impact on cell viability.
介电泳（DEP）是一种用于对细胞进行无标记分选的强大工具，即使是那些在形态和介电特性上存在细微差异的细胞。然而，一个主要限制是，大多数现有的DEP技术仅能以低通量（<1 mL/h）高效地分选细胞。在此，我们证明，在主要的DEP分选区域上游集成一个三维（3D）耦合流体动力学-DEP细胞预聚焦模块，与传统的DEP方法相比，能够使细胞分选通量提高10倍。为了更好地理解高通量细胞分离的关键原理和要求，我们提出了一个综合理论模型，以研究在高流速条件下作用于细胞上的流体动力学和静电力的尺度效应。基于该模型，我们表明，在我们所提出的微流控平台中，为了实现高效的细胞分选，关键的细胞与电极距离需要≤10 µm，特别是在流速≥1 mL/h时。基于这些发现，我们开发了一个计算流体动力学模型和粒子跟踪分析，以找到耦合流体动力学-DEP 3D聚焦模块的最佳操作参数（例如流速比和电场）。使用这些最佳参数，我们通过实验证明了能够以高达10 mL/h（>150,000个细胞/分钟）的速率对活/死K562细胞进行分选，分选纯度为90%，细胞回收率为85%，并且对细胞活力没有负面影响。
