Locomotion, wrinkling, and budding of a multicomponent vesicle in viscous fluids
Locomotion, wrinkling, and budding of a multicomponent vesicle in viscous fluids
复制标题
粘性液体中多组分囊泡的运动、起皱和出芽
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
A. Voigt
中科院分区：
文献类型：
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作者：
Shuwang Li;J. Lowengrub;A. Voigt
最近对巨型单层囊泡（GUV）的实验结果表明，膜表面混合的多种脂质成分可能会分解成具有不同成分的共存相，并伴随表面形态的变化。演化的驱动力包括弯曲、沿相边界的线张力、不均匀表面能和流体力。在这里，我们有兴趣探索当存在流动时，特别是当共存相的表面张力不同时出现的形态，这是以前没有考虑到的。在本文中，我们提出了一个能够描述流动、膜形态和表面相演化之间非线性耦合的模型。使用能量变化方法，我们推导了广义表面张力并构建了连接表面张力和相位变量的本构方程。为了研究非线性动力学，我们开发了一种数值方法，结合了求解流动方程的浸入界面法、捕获界面运动的水平集方法、求解演化表面上的相场方程的非刚性欧拉算法以及强制全局不可扩展性的惩罚项。我们的数值结果表明，非均匀表面张力与流动一起引入了非平凡的囊泡动力学，包括运动、起皱和出芽。
Recent experimental results on giant unilamellar vesicles (GUVs) show that mixed multiple lipid components on the surface of a membrane may decompose into coexisting phases with distinct compositions, with concomitant changes in the surface morphology. The driving forces for the evolution involves bending, line tension along the phase boundaries, inhomogeneous surface energy, and fluid forces. Here we are interested in exploring the emergent morphologies when the flow is present, and in particular when the surface tensions of the coexisting phases are different, which has not been considered previously. In this paper, we present a model capable of describing the nonlinear coupling among flow, membrane morphology, and the evolution of the surface phases. Using an energy variation approach, we derive a generalized surface tension and construct a constitutive equation connecting the surface tension and the phase variables. To investigate the nonlinear dynamics, we develop a numerical method that combines the immersed interface method to solve the flow equations, the level-set method to capture the interface motion, a non-stiff Eulerian algorithm to solve the phase field equations on the evolving surface, and a penalty term that enforces global inextensibility. Our numerical results suggest that the nonhomogeneous surface tension, together with the flow, introduces nontrivial vesicle dynamics including locomotion, wrinkling, and budding.
影响因子：
3.4
作者：
Veatch, SL;Keller, SL
通讯作者：
Keller, SL