The electroporation system can serve as a tool for the intracellular delivery of foreign cargos. However, this technique is presently limited by the inaccurate electric field applied to the single cells and lack of a real-time electroporation metrics subsystem. Here, we reported a microfluidic system for precise and rapid single-cell electroporation and simultaneous impedance monitoring in a constriction microchannel. When single cells (A549) were continuously passing through the constriction microchannel, a localized high electric field was applied on the cell membrane, which resulted in highly efficient (up to 96.6%) electroporation. During a single cell entering the constriction channel, an abrupt impedance drop was noticed and demonstrated to be correlated with the occurrence of electroporation. Besides, while the cell was moving in the constriction channel, the stabilized impedance showed the capability to quantify the electroporation extent. The correspondence of the impedance variation and electroporation was validated by the intracellular delivery of the fluorescence indicator (propidium iodide). Based on the obtained results, this system is capable of precise control of electroporation and real-time, label-free impedance assessment, providing a potential tool for intracellular delivery and other biomedical applications.

中文翻译：

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使用收缩微通道实时阻抗评估的单细胞电穿孔。

电穿孔系统可以用作细胞内递送外来货物的工具。但是，该技术目前受到施加到单个细胞的不准确电场和缺乏实时电穿孔指标子系统的限制。在这里，我们报道了一种微流体系统，用于在收缩微通道中进行精确，快速的单细胞电穿孔和同时阻抗监测。当单细胞（A549）连续通过收缩微通道时，在细胞膜上施加了局部高电场，这导致了高效（高达96.6％）的电穿孔。在单个细胞进入收缩通道的过程中，注意到突然的阻抗下降，并证明与电穿孔的发生有关。除了，当细胞在收缩通道中移动时，稳定的阻抗显示了量化电穿孔程度的能力。通过细胞内递送荧光指示剂（碘化丙啶）验证了阻抗变化和电穿孔的对应关系。基于获得的结果，该系统能够精确控制电穿孔和实时，无标记的阻抗评估，为细胞内递送和其他生物医学应用提供了潜在的工具。