Shivers Jordan L, Nguyen Michael, Dinner Aaron R, Vlahovska Petia M, Vaikuntanathan Suriyanarayanan
The James Franck Institute, University of Chicago, Chicago, Illinois USA.
Department of Chemistry, University of Chicago, Chicago, Illinois USA.
ArXiv. 2025 Mar 31:arXiv:2503.24120v1.
Uncovering the rules governing the nonequilibrium dynamics of the membranes that define biological cells is of central importance to understanding the physics of living systems. We theoretically and computationally investigate the behavior of model protocells-flexible quasispherical vesicles-that exchange membrane constituents, internal volume, and heat with an external reservoir. The excess chemical potential and osmotic pressure difference imposed by the reservoir act as generalized thermodynamic driving forces that modulate vesicle morphology. We identify an associated nonequilibrium morphological transition between a weakly driven regime, in which growing vesicles remain quasispherical, and a strongly driven regime, in which vesicles accommodate rapid membrane uptake by developing surface wrinkles. This transition emerges due to the renormalization of membrane mechanical properties by nonequilibrium driving. Further, using insights from stochastic thermodynamics we propose a minimal vesicle growth-shape law that remains robust even in strongly driven, far-from-equilibrium regimes.
揭示支配界定生物细胞的膜的非平衡动力学的规则对于理解生命系统的物理学至关重要。我们通过理论和计算研究了模型原始细胞（柔性准球形囊泡）的行为，这些囊泡与外部储库交换膜成分、内部体积和热量。储库施加的过量化学势和渗透压差异充当调节囊泡形态的广义热力学驱动力。我们确定了一种相关的非平衡形态转变，即在弱驱动状态下，生长的囊泡保持准球形，而在强驱动状态下，囊泡通过形成表面皱纹来适应快速的膜摄取。这种转变是由于非平衡驱动对膜力学性质的重整化而出现的。此外，利用随机热力学的见解，我们提出了一个最小的囊泡生长形状定律，即使在强驱动、远离平衡的状态下也依然稳健。
