(208b) Flow-through Electroporation for Large-Volume Transfection of Cells

Genetically modified cells with enhanced functions have emerged as promising materials in cell-based therapies such as cancer immunotherapy, stem cell therapy and tissue regeneration. In these applications, cell samples of large volume (10⁸-10⁹ cells) are often processed for transfection. This poses new challenges for current transfection methods and practices. Here we present a flow-through electroporation method for the delivery of genes into cells at high flow rates based on a disposable fluidic chip with alternating wide and narrow sections, a syringe pump and a low-cost direct current (DC) power supply. We tested the delivery of plasmids encoding enhanced green fluorescent protein (pEFGP-C1) into Chinese hamster ovary (CHO-K1) cells in the devices of various dimensions and geometries. Cells were mixed with the plasmids and then flowed through a fluidic channel continuously while a constant voltage was established across the device. The effects of electrical field strength and cell residence time in both narrow and wide sections on transfection efficiency and cell viability were studied. Together with the applied voltage, the geometry and dimensions of the fluidic channel determined the electrical parameters of the electroporation. With the optimal design, 75% of the viable cells were transfected after the procedure, and the throughput could reach up to 2.6 × 10⁷ cells/min. We also generalize the guidelines for scaling up these flow-through electroporation devices. We envision that this technique will serve as a generic and low-cost tool for a variety of clinical applications requiring large volume of transfected cells.