  This paper presents a model and numerical analysis (simulations) of
transmembrane potential induced in biological cell membrane under the influence
of externally applied electric field (i.e., electroporation). This model
differs from the established models of electroporation in two distinct ways.
Firstly, it incorporates the presence of cholesterol (~20% mole-fraction) in
biological membrane. Secondly, it considers the distribution of pores as a
function of the variation of transmembrane potential from one region of the
cell to another. Formulation is based on the role of membrane tension and
electrical forces in the formation of pores in a cell membrane, which is
considered as an infinitesimally thin insulator. The model has been used to
explore the process of creation and evolution of pores and to determine the
number and size of pores as a function of applied electric field (magnitude and
duration). Results show that the presence of cholesterol enhances poration by
changing the membrane tension. Analyses indicate that the number of pores and
average pore radii differ significantly from one part of the cell to the other.
While some regions of the cell membrane undergo rapid and dense poration,
others remain unaffected. The method can be a useful tool for a more realistic
prediction of pore formation in cells subjected to electroporation.
