Parallel Recordings of Transmembrane hERG Channel Currents Based on Solvent-Free Lipid Bilayer Microarray

Abstract

The reconstitution of ion-channel proteins in artificially formed bilayer lipid membranes (BLMs) forms a well-defined system for the functional analysis of ion channels and screening of the effects of drugs that act on these proteins. To improve the efficiency of the BLM reconstitution system, we report on a microarray of stable solvent-free BLMs formed in microfabricated silicon (Si) chips, where micro-apertures with well-defined nano- and micro-tapered edges were fabricated. Sixteen micro-wells were manufactured in a chamber made of Teflon®, and the Si chips were individually embedded in the respective wells as a recording site. Typically, 11 to 16 BLMs were simultaneously formed with an average BLM number of 13.1, which corresponded to a formation probability of 82%. Parallel recordings of ion-channel activities from multiple BLMs were successfully demonstrated using the human ether-a-go-go-related gene (hERG) potassium channel, of which the relation to arrhythmic side effects following drug treatment is well recognized.

Lateral voltage as a new input for artificial lipid bilayer systems

“…In previous studies, we used micro-fabricated Si chips as membrane supports to form BLMs and applied them to producing biosensors and light sensing devices. 10,17,21 On the other hand, Teon lms have traditionally been used as a support for BLMs in functional analyses of ion channel activities. 6,22,23 In this study, we developed suitable processes for fabricating electrodes on these Teon lms and Si chips.…”

Lipid bilayer platforms for parallel ion channel recordings

“…6(a)], enable extremely stable aperture-suspended bilayers, as quantified by aspiration cycles, centrifugal force, large changes to the applied potential and by bilayer lifetime. 9) Recently, a 4 × 4 array of shaped apertures was reported by Miyata et al 32) As illustrated in Fig. 6, a vertically oriented holder for 16 aperture chips was initially flanked by two aqueous compartments of 1.4 ml volume.…”

“…Current recordings of the 16 bilayers were obtained with a 16-channel patch clamp amplifier, with a vertical common ground electrode in the shared trans compartment. 32) Despite the associated mechanical and electrical perturbations, 13 bilayers were formed on average. Miyata et al typically observed hERG ion channel activity, in 120 mM KCl at −100 mV, in six bilayers simultaneously.…”

“…Miyata et al typically observed hERG ion channel activity, in 120 mM KCl at −100 mV, in six bilayers simultaneously. 32) Proteoliposome fusion is more demanding than using self-inserting ion channels but fusion can be facilitated, for example by centrifugation at ∼40 × g. 33)…”

“…8(a)] is extremely stable. 32) The panels are adapted (CC BY 4.0) from the original publications. 9,32) SC0804-5 © 2022 The Author(s).…”