Simultaneous confocal and electrophysiological assessment of membrane properties and ion channel activity in a microfluidic format - a powerful combination for drug development

Alterations in the cell membrane properties can indirectly influence ion channel function. Here, we present a microfluidic device for simultaneous confocal and electrophysiological measurements to study the influence of cholesterol on bilayer models, while recording the activity of gramicidin. Our results reveal that the addition of cholesterol (15 & 40% mol) leads to thinning of the bilayer and a reduced fluidity. Concurrently, the gramicidin activity drops and the single channel lifetime becomes shorter, while both the measured decrease in bilayer thickness and fluidity are expected to cause the opposite, suggesting that other (mechanical) bilayer properties play an important role to modulate the gramicidin activity.