On-Demand Self-Assembly of Supported Membranes Using Sacrificial, Anhydrobiotic Sugar Coats

Abstract

Borrowing principles of anhydrobiosis, we have developed a technique for self-assembling proteolipid-supported membranes on demand--simply by adding water. Intact lipid- and proteolipid vesicles dispersed in aqueous solutions of anhydrobiotic trehalose are vitrified on arbitrary substrates, producing glassy coats encapsulating biomolecules. Previous efforts establish that these carbohydrate coats arrest molecular mobilities and preserve native conformations and aggregative states of the embedded biomolecules, thereby enabling long-term storage. Subsequent rehydration, even after an extended period of time (e.g., weeks), devitrifies sugar--releasing the cargo and unmasking the substrate surface--thus triggering substrate-mediated vesicle fusion in real time, producing supported membranes. Using this method, arrays of membranes, including those functionalized with membrane proteins, can be readily produced in situ by spatially addressing vitrification using common patterning tools--useful for multiplexed or stochastic sensing and assaying of target interactions with the fluid and functional membrane surface.

On-Demand Formation of Supported Lipid Membrane Arrays by Trehalose-Assisted Vesicle Delivery for SPR Imaging

“…During the vitrification of trehalose and removal of water from the environment, embedded SUVs undergo significant shape deformation, which is restored once water is added back to the system. 16 This shape deformation likely plays an important role in determining minimum distances for eliminating cross talk of adjacent spots, as this may cause the bulk deposited vesicle surface area to laterally stretch from the arrayed spot. Nevertheless, this does not seem to have any negative impact on results, even with spacing <100 μm.…”

“…Nevertheless, this does not seem to have any negative impact on results, even with spacing <100 μm. 16 This was further explored by spotting a microarray substrate for biological recognition, that on hydration resulted in 800 × 800 μm POPC membranes containing either GM1, GM2, GM3, or no receptors, as a negative control. Previous work has shown that cholera toxin has a very low affinity toward GM2 and GM3 compared to GM1 and no affinity toward POPC alone.…”

“…Resulting lipid bilayers on glass were studied by fluorescence microscopy, and were shown having fluidity comparable to conventional SLBs, as well as being capable of maintaining embedded ligands and receptors in their active state throughout the trehalose vitrification and devitrification processes. 16 Compared to fluorescence, label-free analytical methods such as surface plasmon resonance (SPR) allow for the characterization of molecular interactions in a highly efficient fashion without extra labeling or tagging steps, thereby eliminating potential interference and labor. 19 SPR assays have successfully been applied toward studying a large variety of chemical and biological samples, 20 and are user-friendly enough to be conducted in clinical settings.…”

Bioinspired assemblies and plasmonic interfaces for electrochemical biosensing

“…5). More recent efforts have been made to preserve membrane structure during storage and transport, which may have important implications toward advancing commercialization and widespread adaptation of these biomimetic interfaces [77, 78]. …”

Novel biomedical applications of supported lipid bilayers

“…Recently, trehalose has been used to prepare storable and triggered substrate-mediated vesicle fusion. 151 Addition of a synthetic trehalose glycolipid provided air stability at doping densities as low as 20% in the case of supported lipid monolayers.…”