The fabrication of large-scale, solid-supported
lipid bilayer (SLB)
arrays has traditionally been an arduous and complex task, primarily
due to the need to maintain SLBs within an aqueous environment. In
this work, we demonstrate the use of trehalose vitrified phospholipid
vesicles that facilitate on-demand generation of microarrays, allowing
each element a unique composition, for the label-free and high-throughput
analysis of biomolecular interactions by SPR imaging (SPRi). Small,
unilamellar vesicles (SUVs) are suspended in trehalose, deposited
in a spatially defined manner, with the trehalose vitrifying on either
hydrophilic or hydrophobic SPR substrates. SLBs are subsequently spontaneously
formed on-demand simply by in situ hydration of the array in the SPR
instrument flow cell. The resulting SLBs exhibit high lateral mobility,
characteristic of fluidic cellular lipid membranes, and preserve the
biological function of embedded cell membrane receptors, as indicated
by SPR affinity measurements. Independent fluorescence and SPR imaging
studies show that the individual SLBs stay localized at the area of
deposition, without any encapsulating matrix, confining coral, or
boundaries. The introduced methodology allows individually addressable
SLB arrays to be analyzed with excellent label-free sensitivity in
a real-time, high-throughput manner. Various protein–ganglioside
interactions have been selected as a model system to illustrate discrimination
of strong and weak binding responses in SPRi sensorgrams. This methodology
has been applied toward generating hybrid bilayer membranes on hydrophobic
SPR substrates, demonstrating its versatility toward a range of surfaces
and membrane geometries. The stability of the fabricated arrays, over
medium to long storage periods, was evaluated and found to be good.
The highly efficient and easily scalable nature of the method has
the potential to be applied to a variety of label-free sensing platforms
requiring lipid membranes for high-throughput analysis of their properties
and constituents