Translocation kinetics of vesicles through narrow pores

Bulgarian Academy of Sciences, Institute of Physical Chemistry - 1113 Sofia, Bulgaria

^(a) milchev@ipc.bas.bg (corresponding author)

Received: 23 December 2021
Accepted: 2 May 2022

Abstract

We use extensive Molecular Dynamics (MD) simulations to study the osmotically induced translocation of partially filled vesicles through narrow pores. The dependence of the average translocation time, , on vesicle size M, pore radius R_p, and strength of the driving force, , is examined for vesicles in a broad interval of sizes M. The time is found to grow with decreasing pore size by an universal scaling law, , where denotes the critical pore radius when the vesicle gets stuck in the pore. With regard to applied pressure, P, we find a power law relationship, , where with P_cr being the least pressure that can still drive the vesicle through a pore of size R_p. The exponent ω varies with R_p and tends to unity as the pore size narrows, . In addition, is found to attain a minimum for an optimal value of the membrane bending rigidity. The variation of vesicle shape, surface area, volume and translocated fraction of the vesicle with time elapsed since the onset of the process is shown to change qualitatively with varying pore size.