A microfluidic biochip for the nanoporation of living cells

Abstract

This paper deals with the development of a microfluidic biochip for the exposure of living cells to nanosecond pulsed electric fields (nsPEF). When exposed to ultra short electric pulses (typical duration of 3 to 10 ns), disturbances on the plasma membrane and on the intra cellular components occur, modifying the behavioral response of cells exposed to drugs or transgene vectors. This phenomenon permits to envision promising therapies. The presented biochip is composed of thick gold electrodes that are designed to deliver a maximum of energy to the biological medium containing cells. The temporal and spectral distributions of the nsPEF are considered for the design of the chip. In order to validate the fabricated biochip ability to orient the pulse towards the cells flowing within the exposition channels, a frequency analysis is provided. High voltage measurements in the time domain are performed to characterize the amplitude and the shape of the nsPEF within the exposition channels and compared to numerical simulations achieved with a 3D Finite-Difference Time-Domain code. We demonstrate that the biochip is adapted for 3 ns and 10 ns pulses and that the nsPEF are homogenously applied to the biological cells regardless their position along the microfluidic channel. Furthermore, biological tests performed on the developed microfluidic biochip permit to prove its capability to permeabilize living cells with nanopulses. To our knowledge, we report here the first successful use of a microfluidic device optimized for the achievement and real time observation of the nanoporation of living cells.

Technological and Theoretical Aspects for Testing Electroporation on Liposomes

“…Different types of applicators and devices can be used without compromising the shape of the applied pulse [16–21]. Moreover, with the advances in micro- and nanofabrication techniques, some microdevices are proposed for nanosecond exposure, integrated also with a microfluidic system [16, 19, 22, 23]. A typical applicator is a standard electroporation cuvette consisting of two plate parallel electrodes with a gap of 4, 2, or 1 mm [12, 13, 18, 20].…”

A versatile high voltage nano- and sub-nanosecond pulse generator

“…Compared to the previously-reported microstrip-based pulser, this device allows the generation of pulses of higher intensitiy and with more flexible duration. This generator can now be used to investigate the effects of intense nanosecond and subnanosecond pulses on biological cells or tissues when combined to specific pulse delivery systems via coaxial cables [39][40][41][42]. However, one should be aware that depending on the pulse applicator (electroporation cuvettes, microchambers, microfluific biochips,…), the pulse across the biological load can be significantly different from the pulse measured across an ideal 50 Ω load, especially when the pulse duration decreases [33].…”

Electrical analysis of cell membrane poration induced by an intense nanosecond pulsed electric field, using an atomistic-to-continuum method

“…The electric fields are assessed inside a liquid biological target exposed to nsPEFs either within an electroporation cuvette [18,19], a transverse electromagnetic cell [20,21] or within thin electrodes [22][23][24]. We have also carried out numerical studies of the electric field induced at a single cell level when a very simplified cell model is placed between two electrodes and exposed to nsPEFs [5].…”