Dynamic Morphologies and Stability of Droplet Interface Bilayers

Abstract

We develop a theoretical framework for understanding dynamic morphologies and stability of droplet interface bilayers (DIBs), accounting for lipid kinetics in the monolayers and bilayer, and droplet evaporation due to imbalance between osmotic and Laplace pressures. Our theory quantitatively describes distinct pathways observed in experiments when DIBs become unstable. We find that when the timescale for lipid desorption is slow compared to droplet evaporation, the lipid bilayer will grow and the droplets approach a hemispherical shape. In contrast, when lipid desorption is fast, the bilayer area will shrink and the droplets eventually detach. Our model also suggests there is a critical size below which DIBs can become unstable, which may explain experimental difficulties in miniaturizing the DIB platform.

Activating mechanosensitive channels embedded in droplet interface bilayers using membrane asymmetry

“…We hypothesise that the increased activation threshold may be due to LPC partitioning between the DIB and droplet monolayers or into the bulk hexadecane. 72 These mechanisms would reduce the effective LPC concentration in the bilayer to minimise the destabilising effect of the lyso-lipid 73 and hence minimise the free energy of the system.…”

Measuring bilayer surface energy and curvature in asymmetric droplet interface bilayers

“…The present model is valid for stationary surfaces at equilibrium. It would also be interesting to extend the model to dynamic behaviour of micro-DIBs where the droplets change shape and the bilayer may even buckle [60]. The bilayer buckling indicates that the effective bilayer surface tension g b had dropped to zero [5].…”

“…It would also be interesting to extend the model to dynamic behaviour of micro-DIBs where the droplets change shape and the bilayer may even buckle. (60) The bilayer buckling indicates that the effective bilayer surface tension 𝛾 𝑏 had dropped to zero. ( 5) Understanding interfacial physical chemistry is paramount to the development of DIBs as a tool for biological discovery, which is crucial for burgeoning fields such as synthetic biology and biotechnology.…”

UV-DIB: label-free permeability determination using droplet interface bilayers

“…Within DIB literature it is known that ‘zip up’ time refers to drainage of any residual oil between monolayer leaflets. 47,48 The clear exponential character of the curves supports assumption of continuous DIB area following zip up. When determining permeability from concentration–time curves, care was taken to extract this coefficient from data after zip up of the DIB had occurred.…”