Frequency-Dependent Electroformation of Giant Unilamellar Vesicles in 3D and 2D Microelectrode Systems

Abstract

A giant unilamellar vesicle (GUV), with similar properties to cellular membrane, has been widely studied. Electroformation with its simplicity and accessibility has become the most common method for GUV production. In this work, GUV electroformation in devices with traditional 3D and new 2D electrode structures were studied with respect to the applied electric field. An optimal frequency (10 kHz in the 3D and 1 kHz in the 2D systems) was found in each system. A positive correlation was found between GUV formation and applied voltage in the 3D electrode system from 1 to 10 V. In the 2D electrode system, the yield of the generated GUV increased first but decreased later as voltage increased. These phenomena were further confirmed by numerically calculating the load that the lipid film experienced from the generated electroosmotic flow (EOF). The discrepancy between the experimental and numerical results of the 3D electrode system may be because the parameters that were adopted in the simulations are quite different from those of the lipid film in experiments. The lipid film was not involved in the simulation of the 2D system, and the numerical results matched well with the experiments.

Anomalous Colloidal Motion under Strong Confinement

“…GUVs were formed following a single step electroformation procedure based on the application of an electrical field with a constant value of the frequency and voltage to the electroformation chamber for a fixed time of 1 h. [ 30,45,46 ] In order to obtain GUVs with different diameters, the frequency and voltage of the applied electric field were varied in the range 10 1 –10 4 Hz and 2–10 V, respectively. The formation of GUVs in such frequency and voltage ranged may be related to the existence of an optimal electro‐osmotic flow for the hydration and swelling of the initial lipid film, [ 47 ] and therefore the absence of GUV formation when an electric films with low voltage and high frequency is applied can be explained in terms of the weakness and high velocity of the electro‐osmotic vibrations, which limit the swelling process of the film.…”

Editorial for the Special Issue on Micro/Nano-Chip Electrokinetics

“… Other electric field-based applications. Wang et al [ 14 ] investigated the frequency-dependent electroformation of giant unilamellar vesicles in between 3D and 2D microelectrode systems. Liu et al [ 15 ] presented a new method for analyzing the deformability of fused cells under electrical stresses in a microfluidic array device.…”