Size Specific Transfection to Mammalian Cells by Micropillar Array Electroporation

Abstract

Electroporation serves as a promising non-viral gene delivery approach, while its current configuration carries several drawbacks associated with high-voltage electrical pulses and heterogeneous treatment on individual cells. Here we developed a new micropillar array electroporation (MAE) platform to advance the electroporation-based delivery of DNA and RNA probes into mammalian cells. By introducing well-patterned micropillar array texture on the electrode surface, the number of pillars each cell faces varies with its plasma membrane surface area, despite their large population and random locations. In this way, cell size specific electroporation is conveniently carried out, contributing to a 2.5~3 fold increase on plasmid DNA transfection and an additional 10–55% transgene knockdown with siRNA probes, respectively. The delivery efficiency varies with the number and size of micropillars as well as their pattern density. As MAE works like many single cell electroporation are carried out in parallel, the electrophysiology response of individual cells is representative, which has potentials to facilitate the tedious, cell-specific protocol screening process in current bulk electroporation (i.e., electroporation to a large population of cells). Its success might promote the wide adoption of electroporation as a safe and effective non-viral gene delivery approach needed in many biological research and clinical treatments.

Tracking the Evolution of Transiently Transfected Individual Cells in a Microfluidic Platform

“…In the same vein, the topography-induced increase of the cell size (e.g. using micropillars) in 2D also resulted in a significant increased the transfection efficiency 32 .…”

Intracellular delivery of mRNA to human primary T cells with microfluidic vortex shedding

“…In general, microfluidic methods have improved macromolecule delivery into cells by scaling microfluidic channel geometries with cell dimensions. Intracellular delivery methods utilizing microfluidics include electroporation 14–16 , microinjection 17 , cell constriction or squeezing 18–23 , fluid shear 24,25 and electrosonic jet ejection 26,27 . These methods offer appealing alternatives to conventional transfection systems, however, their production output (i.e.…”

Biosensors Based on Mechanical and Electrical Detection Techniques

“…Micropillar (MP) sensors are sensitive to mechanical deformation both transiently and continuously [ 78 , 79 ], and are relatively simple to fabricate (using silicon lithography techniques) [ 80 , 81 ] and to operate [ 80 ]. They function in a similar manner to MCs, but without the functionalised surface.…”

“…Generally, the deflection of the pillar creates a stress on a piezoresistive material, changing the impedance of the circuit [ 79 , 82 ]. They are often used as arrays to detect forces exerted by cells through the deformation of the pillars [ 80 , 81 ]. This technique has great potential, though the current method of measurement using digital image correlation is slow and cumbersome [ 83 ].…”