Long-term storable and shippable lipid bilayer membrane platform

Abstract

The fragility and short lifetimes characteristic of conventionally formed lipid bilayer membranes has necessitated their preparation to be at the time and point of use. By using high freezing-point lipid-solvent mixtures, the process of lipid bilayer self-assembly may be reversibly arrested. In solid form, the bilayer precursor can be stored indefinitely and is sufficiently robust to withstand commercial shipping. Upon thawing, bilayer self-assembly resumes, resulting in a biologically functional membrane. Combination of this membrane precursor with an inexpensive chip results in a compact, practical, and disposable platform for ion channel measurements.

Automatable production of shippable bilayer chips by pin tool deposition for an ion channel measurement platform

“…To eliminate the requirement for the preparation of the bilayers at the time and place of measurement, we recently demonstrated lipid bilayer formation from a freezable precursor [8]. In this system, lipids are dissolved in a high freezing point solvent such as hexadecane (T f = 18°C) and spread over an orifice in a hydrophobic plastic such as Teflon or Delrin (similar to standard methods [3,9]).…”

“…Teflon partitions (Eastern Scientific) containing five orifices 500 μm in diameter were placed between two halves of a 5 × 1 array of chambers machined from acrylic (McMaster-Carr) containing fluidic inlets, as described previously [8]. Other partitions for bilayer precursor solution deposition and subsequent bilayer formation were made from 76 μm thick acetal homopolymer film (CS Hyde Co.).…”

“…After transferring the solvent to the film the chamber was placed in a 4°C refrigerator where the solvent froze across the aperture. The bilayers with the deposited solution were stored for long periods, similarly to our previously reported work [8].…”

Microfluidic platform for bilayer experimentation

“…44,[46][47][48] This phenomenon is exploited here to indirectly compare the properties of membranes prepared from (1) DPhPC in ndecane, (2) DPhPC in n-decane supplemented with 2% vol ethanol, and (3) DPhPC in n-decane exposed to acetylsalicylic acid (1 µM in 1 M KCl buffer) ( Figure 3.7 a-c).…”

“…42 Finally, in another report, the lipid plug was frozen prior to thinning, and spontaneously formed a bilayer upon thawing, with a success yield of up to 50%. 47 In contrast, if the aperture-containing substrate is thicker, thinning must be assisted by applying an external force. For instance, hydrostatic pressure was employed to induce thinning of a lipid plug deposited in a 47-µm thick PMMA substrate (100-µm diameter aperture), reaching a success yield of 90%.…”