From supported membranes to tethered vesicles: lipid bilayers destabilisation at the main transition

TL;DR

This study investigates how supported phospholipid bilayers destabilize and form tethered vesicles during the main phase transition, highlighting the role of bending rigidity and adhesion energy in this process.

Contribution

It provides a detailed analysis of bilayer destabilization at the main transition, linking experimental observations to theoretical scaling arguments.

Findings

Unbinding occurs around the main transition temperature.

Formation of monodisperse tethered vesicles.

Destabilization driven by decreased bending rigidity and weak adhesion.

Abstract

We report results concerning the destabilisation of supported phospholipid bilayers in a well-defined geometry. When heating up supported phospholipid membranes deposited on highly hydrophilic glass slides from room temperature (i.e. with lipids in the gel phase), unbinding was observed around the main gel to fluid transition temperature of the lipids. It lead to the formation of relatively monodisperse vesicles, of which most remained tethered to the supported bilayer. We interpret these observations in terms of a sharp decrease of the bending rigidity modulus $\kappa$ in the transition region, combined with a weak initial adhesion energy. On the basis of scaling arguments, we show that our experimental findings are consistent with this hypothesis.