In situ electroporation of mammalian cells through SiO2 thin film capacitive microelectrodes

M Maschietto,S Vassanelli,M Dal Maschio,S Girardi

doi:10.1038/s41598-021-94620-8

Abstract

Electroporation is a widely used non-viral technique for the delivery of molecules, including nucleic acids, into cells. Recently, electronic microsystems that miniaturize the electroporation machinery have been developed as a new tool for genetic manipulation of cells in vitro, by integrating metal microelectrodes in the culture substrate and enabling electroporation in-situ. We report that non-faradic SiO2 thin film-insulated microelectrodes can be used for reliable and spatially selective in-situ electroporation of mammalian cells. CHO-K1 and SH-SY5Y cell lines and primary neuronal cultures were electroporated by application of short and low amplitude voltage transients leading to cell electroporation by capacitive currents. We demonstrate reliable delivery of DNA plasmids and exogenous gene expression, accompanied by high spatial selectivity and cell viability, even with differentiated neurons. Finally, we show that SiO2 thin film-insulated microelectrodes support a double and serial transfection of the targeted cells.

Highlights

Electroporation is a widely used non-viral technique for the delivery of molecules, including nucleic acids, into cells
We demonstrate that in-situ electroporation of mammalian cells can be achieved efficiently through a SiO2 thin film that, to other oxide films, is known to largely suppress faradaic currents[35,36,37,38,39,40]
In these experiments we demonstrated the transfection using a plasmid coding for the Enhanced Yellow Fluorescent Protein (EYFP) (Fig. 4a–c)

Summary

Introduction

Electroporation is a widely used non-viral technique for the delivery of molecules, including nucleic acids, into cells. Electronic microsystems that miniaturize the electroporation machinery have been developed as a new tool for genetic manipulation of cells in vitro, by integrating metal microelectrodes in the culture substrate and enabling electroporation in-situ. On-chip microdevices based on integrated active sites are promising tools for selective in-situ electroporation and transfection of adherent cells, and has been proven with a variety of cell types including primary c ultures[27,28,29] and transfection molecules comprising DNA for exogenous gene expression or short oligonucleotides for RNA interference[27,30,31,32,33]. We validate the method by demonstrating high transfection efficiency and cell selectivity for exogenous gene expression and by performing double serial transfections of adherent mammalian cells, including primary neurons

Methods

Results

Conclusion