Jump to main content
Jump to site search

Issue 37, 2015
Previous Article Next Article

Viscoelastic deformation of lipid bilayer vesicles

Author affiliations

Abstract

Lipid bilayers form the boundaries of the cell and its organelles. Many physiological processes, such as cell movement and division, involve bending and folding of the bilayer at high curvatures. Currently, bending of the bilayer is treated as an elastic deformation, such that its stress–strain response is independent of the rate at which bending strain is applied. We present here the first direct measurement of viscoelastic response in a lipid bilayer vesicle. We used a dual-beam optical trap (DBOT) to stretch 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) giant unilamellar vesicles (GUVs). Upon application of a step optical force, the vesicle membrane deforms in two regimes: a fast, instantaneous area increase, followed by a much slower stretching to an eventual plateau deformation. From measurements of dozens of GUVs, the average time constant of the slower stretching response was 0.225 ± 0.033 s (standard deviation, SD). Increasing the fluid viscosity did not affect the observed time constant. We performed a set of experiments to rule out heating by laser absorption as a cause of the transient behavior. Thus, we demonstrate here that the bending deformation of lipid bilayer membranes should be treated as viscoelastic.

Graphical abstract: Viscoelastic deformation of lipid bilayer vesicles

Back to tab navigation

Supplementary files

Publication details

The article was received on 25 Jun 2015, accepted on 06 Aug 2015 and first published on 06 Aug 2015


Article type: Paper
DOI: 10.1039/C5SM01565K
Author version available: Download Author version (PDF)
Citation: Soft Matter, 2015,11, 7385-7391
  •   Request permissions

    Viscoelastic deformation of lipid bilayer vesicles

    S. Wu, S. Sankhagowit, R. Biswas, S. Wu, M. L. Povinelli and N. Malmstadt, Soft Matter, 2015, 11, 7385
    DOI: 10.1039/C5SM01565K

Search articles by author

Spotlight

Advertisements