Lipid membranes and their applications in analytical biochip devices represent a great tool for the study of membrane dynamics and the related biological phenomena. Lipid-membrane-assisted surfacesensitive sensors have employed to provide biological information as they improve molecular survivability as well as rule out incorrect signals arising from unwanted nonspecific binding between target molecules with sensor surfaces. To enhance the accuracy of the signal as well as the sensitivity of biochip sensors, a variety of strategies have been employed. Here, we introduce various types of in vitro model membrane platforms/techniques and discuss current challenges in the lipid-membrane-assisted surface-sensitive analytical sensors application.

Passive water penetration across the cell membrane by osmotic diffusion is essential for the homeostasis of cell volume, in addition to the protein-assisted active transportation of water. Since membrane components can regulate water permeability, controlling compositional variation during the volume regulatory process is a prerequisite for investigating the underlying mechanisms of water permeation and related membrane dynamics. However, the lack of a viable in vitro membrane platform in hypertonic solutions impedes advanced knowledge of cell volume regulation processes, especially cholesterol-enriched lipid domains called lipid rafts. By reconstituting the liquid-ordered (Lo) domain as a likeness of lipid rafts, we verified suppressed water permeation across the Lo domains, which had yet to be confirmed with experimental demonstrations despite a simulation approach. With the help of direct transfer of the Lo domains from vesicles to supported lipid membranes, the biological roles of lipid composition in suppressed water translocation were experimentally confirmed. Additionally, the improvement in membrane stability under hypertonic conditions was demonstrated based on molecular dynamics simulations.