Dynamics of Force Dipoles in Curved Biological Membranes
Dynamics of Force Dipoles in Curved Biological Membranes
复制标题
弯曲生物膜中力偶极子的动力学
DOI：
10.1021/la201109u
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Rickmoy Samanta
中科院分区：
文献类型：
--
作者：
Sarthak Bagaria;Rickmoy Samanta
我们构建了一个模型来探索弯曲生物膜中活性内含物的流体动力学相互作用。弯曲的膜被建模为高粘性流体的二维层，被不同粘度的外部溶剂包围。活性夹杂物被建模为点力偶极子。点偶极极限是沿着弯曲几何形状的测地线获取的，包含由于曲率而导致的力方向的变化。我们在球形膜的情况下明确地证明了这一点，从而得出了单个夹杂物产生的流动的解析解。我们进一步表明，流场具有由膜拓扑引起的负折射率的额外缺陷，这在模型的平面版本中不存在。最后，我们探索了低曲率和高曲率状态下一对夹杂物的流体动力学相互作用，以及膜外外部流体受到限制的情况。我们的研究表明，在强约束下，偶极子在低曲率和高曲率的弯曲生物膜中聚集。然而，即使在强约束下，非常高的曲率也往往会破坏偶极子聚集。
We construct a model to explore the hydrodynamic interactions of active inclusions in curved biological membranes. The curved membrane is modelled as a two dimensional layer of highly viscous fluid, surrounded by external solvents of different viscosities. The active inclusions are modelled as point force dipoles. The point dipole limit is taken along a geodesic of the curved geometry, incorporating the change in orientation of the forces due to curvature. We demonstrate this explicitly for the case of a spherical membrane, leading to an analytic solution for the flow generated by a single inclusion. We further show that the flow field features an additional defect of negative index, arising from the membrane topology, which is not present in the planar version of the model. We finally explore the hydrodynamic interactions of a pair of inclusions in regimes of low and high curvature, as well as situations where the external fluid outside the membrane is confined. Our study suggests aggregation of dipoles in curved biological membranes of both low and high curvatures, under strong confinement. However, very high curvatures tend to destroy dipole aggregation, even under strong confinement.