Substrate-induced deformation and adhesion of phospholipid vesicles at the main phase transition

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

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Detail(s)

Original languageEnglish
Pages (from-to)245-258
Journal / PublicationBiophysical Chemistry
Volume99
Issue number3
Publication statusPublished - 6 Nov 2002
Externally publishedYes

Abstract

The physiochemical properties of phospholipid vesicle, e.g. permeability, elasticity, etc., are directly modulated by the chain-melting transition of the lipid bilayer. Currently, there is a lack of understanding in the relationship between thermotropic transition, mechanical deformation and adhesion strength for an adherent vesicle at temperature close to main phase transition temperature Tm. In this study, the contact mechanics of dimyristoyl-phosphatidylcholine (DMPC) vesicle at the main phase transition are probed by confocal reflectance interference contrast microscopy in combination with phase contrast microscopy. It is shown that DMPC vesicles strongly adhere on pure fused silica substrate at Tm and the degree of deformation as well as the adhesion energy is a decreasing function against the mid-plane diameter of the vesicles. Furthermore, an increase of osmotic pressure at the gel/liquid crystalline phase co-existence imposes insignificant changes in both the degree of deformation and adhesion energy of adherent vesicles when the lipid bilayer permeability is maximized. With the reverse of substrate charge, the mechanical deformation and adhesion strength for larger vesicles (mid-plane diameter >18 μm) are significantly reduced. By monitoring the parametric response of substrate-induced vesicle adhesion during main phase transition, it is shown that the degree of deformation and adhesion energy of adhering vesicle is increased and unchanged, respectively, against the increase of temperature. © 2002 Published by Elsevier Science B.V.

Research Area(s)

  • Osmotic pressure, Phospholipid, Transition temperature