Microchip-Integrated EOSCs (Electrolyte Oxide Semiconductor Capacitors) as Devices for High Efficiency and Selective Electroporation of Mammalian Cells

Electroporation is a widely used technique for the delivery of molecules in cultured cells. In the last years microchips have been developed for electroporating cells growing in adhesion to the chip substrate. Most part of these devices are based on metal electrodes. Here we show an innovative use of a silicon microchip featuring 64 insulated EOSCs (Electrolyte Oxide Semiconductor Capacitors) to electroporate single or a few mammalian CHO-K1 cells with high efficiency and selectivity. The use of low-voltage pulses allows to maintain a higher cell viability than standard electroporation of cell suspensions. By means of the viability dye Trypan Blue we provide evidencies of both reliability and selectivity of our device. The microchip is presented here as an efficient tool for the delivery of a DNA plasmid to induce the production of the fluorescent protein EYFP, suggesting its possible general use in exogenous genes expression experiments. Finally, we report the application of our device for live imaging in vitro by means of the actin cytoskeletal probe Phalloidin. These results open new perspectives on the possibility of performing alternative live stainings avoiding the chemical fixation of the cells, that is necessary in standard immunofluorescence protocols.