Preservation of Supported Lipid Membrane Integrity from Thermal Disruption: Osmotic Effect

Abstract

Preservation of structural integrity under various environmental conditions is one major concern in the development of the supported lipid membrane (SLM)-based devices. It is common for SLMs to experience temperature shifts from manufacture, processing, storage, and transport to operation. In this work, we studied the thermal adaption of the supported membranes on silica substrates. Homogenous SLMs with little defects were formed through the vesicle fusion method. The mass and fluidity of the bilayers were found to deteriorate from a heating process but not a cooling process. Fluorescence characterizations showed that the membranes initially budded as a result of heating-induced lipid lateral area expansion, followed by the possible fates including maintenance, retraction, and fission, among which the last contributes to the irreversible compromise of the SLM integrity and spontaneous release of the interlipid stress accumulated. Based on the mechanism, we developed a strategy to protect SLMs from thermal disruption by increasing the solute concentration in medium. An improved preservation of the membrane mass and fluidity against the heating process was observed, accompanied by a decrease in the retraction and fission of the buds. Theoretical analysis revealed a high osmotic energy penalty for the fission, which accounts for the depressed disruption. This osmotic-based protection strategy is facile, solute nonspecific, and long-term efficient and has little impact on the original SLM properties. The results may help broaden SLM applications and sustain the robustness of SLM-based devices under multiple thermal conditions.

Design and Construction of a Multi-Tiered Minimal Actin Cortex for Structural Support in Lipid Bilayer Applications

“…These combined functions make actin appropriate for applications in which the molecular properties of lipids and mechanical stability are important. Artificial supports for bilayers mimic the role of the cellular cytoskeleton and are employed throughout biophysics, biomaterials, and bioengineering research, offering a platform for studying membrane properties, cell signaling, membrane–protein interactions, and bilayer functionalization. − Numerous strategies have been developed, such as forming bilayers on hydrated polymer cushions, tethering the bilayer to solid surfaces or microcavities, trapping the bilayer between two hydrogel layers, photopolymerizing reactive amphiphiles in the lipid membrane, cross-linking lipid molecules comprising the bilayer, and polymerizing actin within liposomes …”