Journal ArticleDOI
Vesicular instabilities: The prolate-to-oblate transition and other shape instabilities of fluid bilayer membranes
Marija Jarić,Marija Jarić,Marija Jarić,Udo Seifert,Wolfgang Wintz,Michael Wortis,Michael Wortis,Michael Wortis +7 more
TLDR
A method is exploited for calculating explicitly the stability of arbitrary axisymmetric shapes to map out in a numerically exact way both the stable phases and the metastability of the low-lying shape branches, allowing the full (shape) phase diagram and the full stability diagram to be constructed.Abstract:
The equilibrium shapes of fluid-phase phospholipid vesicles in an aqueous solution are controlled by bending elasticity. The regime of nonvesiculated shapes at reduced volume v\ensuremath{\ge}1/ \ensuremath{\surd}2 involves the interplay of five branches of distinct stationary shapes: pears, prolates, oblates, stomatocytes, plus a branch of nonaxisymmetric shapes with the symmetry ${\mathit{D}}_{2\mathit{h}}$. We exploit a method for calculating explicitly the stability of arbitrary axisymmetric shapes to map out in a numerically exact way both the stable phases and the metastability of the low-lying shape branches. To obtain additional required information about nonaxisymmetric shapes, we calculate these by numerical minimization of the curvature energy on a triangulated surface. Combining these two methods allows us to construct the full (shape) phase diagram and the full stability diagram in this region. We provide explicit results for values of the bending constants appropriate to stearoyl-oleoyl-phosphatidylcholine; generalization to other values is straightforward. (c) 1995 The American Physical Societyread more
Citations
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Configurations of fluid membranes and vesicles
TL;DR: In this article, the authors describe the systematic physical theory developed to understand the static and dynamic aspects of membrane and vesicle configurations, and the preferred shapes arise from a competition between curvature energy which derives from the bending elasticity of the membrane, geometrical constraints such as fixed surface area and fixed enclosed volume, and a signature of the bilayer aspect.
Journal ArticleDOI
Simulating the deformation of vesicle membranes under elastic bending energy in three dimensions
Qiang Du,Chun Liu,Xiaoqiang Wang +2 more
TL;DR: This paper studies the three-dimensional deformation of a vesicle membrane under the elastic bending energy, with prescribed bulk volume and surface area, with a newly developed energetic variational formulation.
Journal ArticleDOI
Mapping vesicle shapes into the phase diagram: A comparison of experiment and theory
TL;DR: This paper presents a large-scale simulation of the response of the immune system to carbon dioxide in the context of a high-pressure environment and shows clear patterns of decline in the immune systems of Response to CO2.
Posted Content
Mapping vesicle shapes into the phase diagram: A comparison of experiment and theory
TL;DR: In this paper, the authors used the area-difference-elasticity (ADE) model of vesicle shapes to characterize the thermal shape ensemble of three prolate vesicles, which, upon heating, experienced a mechanical instability leading to budding.
Journal ArticleDOI
Finite element modeling of lipid bilayer membranes
Feng Feng,William S. Klug +1 more
TL;DR: A numerical simulation framework is presented for the study of biological membranes composed of lipid bilayers based on the finite element method, and how this framework is natural for future investigation of biologically realistic bilayer structures involving nonaxisymmetric geometries, binding and adhesive interactions, heterogeneous mechanical properties, cytoskeletal interactions, and complex loading arrangements.
References
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Journal ArticleDOI
Elastic Properties of Lipid Bilayers: Theory and Possible Experiments
TL;DR: A theory of the elasticity of lipid bilayers is proposed and it is argued that in the case of vesicles (= closed bilayer films) the only elasticity controlling nonspherical shapes is that of curvature.
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The surface evolver
TL;DR: The Surface Evolver is a computer program that minimizes the energy of a surface subject to constraints that is represented as a simplicial complex.
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The minimum energy of bending as a possible explanation of the biconcave shape of the human red blood cell
TL;DR: The concept of bending energy adequately explains the shape of the erythrocyte and predicted a swelling sequence for a single cell which was similar to the observed series of Rand (1967) .
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Entropy-driven tension and bending elasticity in condensed-fluid membranes.
Evan Evans,W. Rawicz +1 more
TL;DR: Sensitive micropipet methods have been used to measure the relation between tension and the projected surface area in fluid membranes of vesicles and confirm the prediction of equilibrium theory that the projected area should increase logarithmically with tension as shape fluctuations become progressively restricted.
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The conformation of membranes
TL;DR: Understanding of many aspects of their conformational behaviour, such as the preferred shapes and shape transformations of closed vesicles, and the shape fluctuations, random-surface configurations, and adhesion and unbinding of interacting membranes, has been improved through fruitful interactions between theory and experiment.