Onsager’s irreversible thermodynamics of the dynamics of transient pores in spherical lipid vesicles

Abstract

Onsager's irreversible thermodynamics is used to perform a systematic deduction of the kinetic equations governing the opening and collapse of transient pores in spherical vesicles. We show that the edge tension has to be determined from the initial stage of the pore relaxation and that in the final state the vesicle membrane is not completely relaxed, since the surface tension and the pressure difference are about 25% of its initial value. We also show that the pore life-time is controlled by the solution viscosity and its opening is driven by the solution leak-out and the surface tension drop. The final collapse is due to a non-linear interplay between the edge and the surface tensions together with the pressure difference. Also, we discuss the connection with previous models.

Generalized Fick–Jacobs Approach for Describing Adsorption–Desorption Kinetics in Irregular Pores under Nonequilibrium Conditions

“…In the context of our model, the explanation of the factor 1/ω in the adsorptive term of Eq. (35) lies directly in the geometric aspects of the reactive interaction between the particles at the bulk and the surface. To explain this, let us consider any point x 0 on the wall of the pore, and a slim slice of width ∆x.…”

Unravelling a Self-healing Thermo- and Hydrodynamic Mechanism of Transient Pore's Late-stage Closing in Vesicles, and Related Soft-matter Systems, in Terms of Liaison Between Surface-tension and Bending Effects

“…Having in mind the increasing interest on vesicles as drug delivery systems, it is worth to examine how the dynamics of transient pores in the membrane of the vesicle can be controlled, as it may constitute a mecha-nism for the capture or delivery of drugs. In this section, we will review the main aspects of irreversible thermodynamics of small systems recently proposed for the description of these phenomena [8].…”

“…[9], where d i S is entropy produced during the infinitesimal transformations dr and dR. Explicitly, these considerations lead to the general expression for the entropy production per unit time [8] T…”

“…In Ref. [8], it was shown by dimensional analysis that these coefficients should be inversely proportional to a product of dynamical viscosity (taken from Newtons' law for the laminar flow) and certain specific lengths. Respectively, the lengths l i s, being included in the L ij s, correspond formally to: (1) formation of the pore (i → r or j → r); (2) formation of the vesicle (i → R or j → R);…”

“…(3) some modus-vivendi compromise of creating a pore of diameter 2r within the vesicle of radius R (i → rR or i → Rr; or, mutatis mutandis the j subscript follows the latter rule); the scalar (and, constant) value of solution's viscosity complement the aforementioned product; for details, see [8].…”