A biomechanical model of electroporation of a biological membrane

Abstract

To describe the mechanism of the electroporation of a biological membrane, a biomechanical model of the critical potential difference /spl Delta//spl Psi//sub 0/ of electroporation has been developed, for a small membrane patch with an equivalent charge q, a mass m, a thickness L, on the positive or the negative side of a membrane and in a direct current pulse field. The model elucidates that: /spl Delta//spl Psi//sub 0/ is proportional to mL/sup 2//q/spl tau/o/sup 2/ and exp(/spl Delta/E/sub d//RT), where /spl tau//sub 0/ is the critical time width of the externally imposed electric pulse, R is the gas constant, T is the absolute temperature of an electroporation system, /spl Delta/E/sub d/(>0) is a thermodynamic energy of molecules in the biological membrane and it has been defined as a net dragging energy between a patch and a membrane. By fitting two sets of experimental data (/spl Delta//spl Psi//sub 0/vs. T),-/spl Delta/E/sub d/ has been estimated in the range of noncovalent bonds (van der Weals, hydrogen and ionic interactions). This result is consistent with the current view of the cohesive forces in biological membranes. Using the model, a set of experimental data of /spl Delta//spl Psi//sub 0/ vs. /spl tau//sub 0/ can be quantitatively fitted well also.