Dynamics of vesicle and cell membranes driven by pressure differences

Abstract

Cell size and shape can be modified by hydrostatic pressure differences between both sides of its membrane. In order to analyze its behavior, two simplified models are evaluated. A model for vesicle expansion based on water uptake is applied to a spherical shaped vesicle. Results show a radius increase up to 20% in a time interval of the order of 10 minutes. On the other hand, we evaluate a model for membrane-cortex adhesion, which is related to membrane deformations due to local detachments. Simulations of the model are done considering both deterministic and stochastic dynamics. Results show that below a pressure difference threshold, only in stochastic simulations a membrane-cortex detachment occurs. Typical times for this process are of the order of 0.1 to 1000 s depending on the detachment condition imposed