The Science and Technology of Automatable Droplet Lipid Bilayer Platforms

Droplet lipid bilayers have been shown to be robust platforms for studying membrane proteins in a highly controlled environment. They are stable and can be formed using automated fluid handling techniques. Measuring membrane protein activity and compound transport through droplet lipid bilayers, however, is labor intensive, and most often requires technicians to manually insert electrodes into small volume droplets. This problem prevents droplet lipid bilayers from being employed in high-throughput measurement platforms. Solutions employing the integration of droplet lipid bilayer formation and measurement are developed in this work. Refinements allowing for simplified control over the size of droplet lipid bilayers for consistent measurements across arrays of bilayers formed in parallel are discussed. The development of a measurement chamber that allows for continuous solution perfusion of intact droplet lipid bilayers is also discussed. These new techniques for forming and measuring droplet lipid bilayers are tested by measuring the drug dose-dependence of activity from ensembles of human ether-a-go-go related gene encoded ion channel (hERG) reconstituted into droplet lipid bilayers. Finally, an automated microfluidic platform allowing for the optical measurement of passive drug permeation through droplet lipid bilayers is developed and discussed. The methods produced in this work indicate that automated formation and measurement of droplet lipid bilayers is feasible. In doing so, they provide the potential to greatly expand the applications of artificial lipid bilayer research