Spatiotemporal Kinetics of Supported Lipid Bilayer Formation on Glass via Vesicle Adsorption and Rupture

Abstract

Supported lipid bilayers (SLBs) represent one of the most popular mimics of the cell membrane. Herein, we have used total internal reflection fluorescence microscopy for in-depth characterization of the vesicle-mediated SLB formation mechanism on a common silica-rich substrate, borosilicate glass. Fluorescently labeling a subset of vesicles allowed us to monitor the adsorption of individual labeled vesicles, resolve the onset of SLB formation from small seeds of SLB patches, and track their growth via SLB-edge-induced autocatalytic rupture of adsorbed vesicles. This made it possible to perform the first quantitative measurement of the SLB front velocity, which is shown to increase up to 1 order of magnitude with time. This effect can be classified as dramatic because in many other physical, chemical, or biological kinetic processes the front velocity is either constant or decreasing with time. The observation was successfully described with a theoretical model and Monte Carlo simulations implying rapid local diffusion of lipids upon vesicle rupture.

Modulating Noncovalent and Covalent Forces to Control Inverse Phosphocholine Lipid Self-Assembly on Inorganic Surfaces

“…6,7 The most common approach to SLB fabrication involves the noncovalent adsorption and spontaneous rupture of nanoscopic lipid vesicles at solid-liquid interfaces. [8][9][10][11][12] Interestingly, this self-assembly process can only occur on a narrow range of surfaces with favorable material properties and mechanistic details continue to be unraveled through experimental, simulation, and theoretical approaches. [13][14][15] There is extensive interest in deciphering why lipid vesicles adsorb and rupture on certain hydrophilic surfaces, but not others, and in translating such chemical insights into the design of improved SLB biointerfaces with tailored properties and stabilities.…”

Ligand-receptor-mediated attachment of lipid vesicles to a supported lipid bilayer

“…Lipid vesicles can often directly attach to solid surfaces and be intact or ruptured and form a supported lipid bilayer [SLB; see e.g. the articles by Cho et al (2010), Mapar et al (2018) and references therein]. Such SLBs can also be fabricated by using other approaches including e.g.…”

“…the articles by Cho et al. ( 2010 ), Mapar et al ( 2018 ) and references therein]. Such SLBs can also be fabricated by using other approaches including e.g.…”

TIRF Microscopy‐Based Monitoring of Drug Permeation Across a Lipid Membrane Supported on Mesoporous Silica

“…Formation of the supported lipid bilayer (SLB) was monitored with TIRF microscopy (Figure 1 A), through the inclusion of rhodamine‐labelled tracer vesicles (Rh‐POPC), [14] on both non‐porous (planar) and MSTF substrates with a pore size of ≈7 nm [12] . The rate of POPC vesicle adsorption and rupture [15] was ≈2‐fold greater on the planar silica substrate, compared to the MSTF, which was attributed to lower adhesion of vesicles to mesoporous silica; however, despite subtle microscopic differences in the actual rupture process, complete SLB formation over the entire surface was observed on both substrates (Figure 1). The integrity of the lipid membrane was verified using FRAP, [16] with substrate‐associated differences being observed for the diffusivity and immobile fraction of labelled Rh‐POPC lipids (Figure 1 C).…”