Dynamics of Hydrogel-Assisted Giant Unilamellar Vesicle Formation from Unsaturated Lipid Systems

Abstract

While current research is centered on observing biophysical properties and phenomena in giant unilamellar vesicles (GUVs), little is known about fabrication parameters that control GUV formation. Using different lipids and rehydration buffers, we directly observe varying dynamics of hydrogel-assisted GUV formation via fluorescence microscopy. We observe the effects of buffer ionic strength, osmolarity, agarose density, and pH on the formation of GUVs using neutral and charged lipids. We find that increasing rehydration buffer ionic strength correlates with increased vesicle size and rate of GUV formation. Increasing buffer acidity increased the rate of GUV formation, while more basic environments slowed the rate. For buffers containing 500 mM sucrose, GUV formation was overall inhibited and only tubules formed. Observations of GUV formation dynamics elucidate parametric effects of charge, ionic strength, pH, and osmolarity, demonstrating the versatility of this biomimetic platform.

Visualization of lipid directed dynamics of perilipin 1 in human primary adipocytes

“…Hydrogel-assisted giant vesicle formation was performed according to established protocols 65 , with the modifications previously described 66 . Briefly, 10 μl of 1% (w/v) molten ultra-low gelling temperature type IX-A agarose (Sigma-Aldrich) were placed onto a plasma-cleaned cover slip (Electro-Technic Inc., USA) and spread evenly by swiping another coverslip across the surface.…”

Fluorescence Approaches for Characterizing Ion Channels in Synthetic Bilayers

“…GUVs can be formed using electroformation, where lipids form GUVs on an electrode surface by inducing an electro-osmotic effect from a voltage current [32]. They can also be produced by swelling hydrogel lipid films [33], gentle hydration of dried lipid films [34], and emulsion-based methods [35].…”

Dewetting-induced formation and mechanical properties of synthetic bacterial outer membrane models (GUVs) with controlled inner-leaflet lipid composition

“…Other methods such as gentle hydration, 38 micropipette jetting, 39,40 and GUV budding assisted by swelling hydrogel films [41][42][43] have been used to build GUVs. Gentle hydration involves the simple rehydration of lipid films with an aqueous solution; however, vesicles formed using this method may display undesirable defects such as vesicles within vesicles and/or lipid aggregates on bilayer leaflets that may hinder their utilization.…”