(755d) Mimicking the Myelin Sheath: Stable and Fluid Multilayer Phospholipid-Silica Thin Films:

Phospholipids are a key component of cell membranes, which act as a physiochemical barrier to compartmentalize cells. The phospholipid molecules are dynamic and fluid in nature within the cell membrane. Transmembrane proteins (TMPs) perform various functions including solute transport, signal transduction, and ATP synthesis. There is enormous interest in developing various model systems including black lipid membrane, liposomes, supported lipid bilayer, and tethered bilayer lipid membrane to study TMPs.  Although significant advancements have been made, very little has been achieved in developing multilamellar structures that are present in the nervous system e.g. myelin and in organelles e.g. mitochondria. Perturbations of myelin, including demyelination is responsible for at least a dozen diseases, most prominent of which is multiple sclerosis (MS). Despite its importance, minimal information on structure-function dynamics are available primarily due to lack of stable multi-lamellar lipid architectures that could be used as experimental models. We have developed two strategies to synthesize stabilized multilamellar lipid architectures: (a) one-step method in which multilamellar lipid template is obtained using spin-coating, which is followed by stabilization using vapors of silica (b) layer-by-layer method in which multilamellar lipid structures are obtained by alternating phospholipid layers, which is stabilized by biotin–avidin chemistry. Multi-lamellar thin films have enhanced stability and maintain fluidity in aqueous solutions. This robust platform will allow us to incorporate TMPs and will be utilized to synthesize rugged materials for device integration with a wide range of applications for mimicking myelin, sensing, and energy harvesting.