Contents I. Introduction
The goal of molecular medicine is to introduce macromolecules such as drugs and gene constructs into specific cells of the body. Some of the better-known molecular medicine techniques include viral vectors [1] and electroporation [2]. Electroporation, which is the focus of this study, is a physical method that uses electrical fields to temporarily increase the permeability of the cell membrane [3]. This permeation facilitates penetration of extracellular macromolecules that could otherwise not enter the cell [4]. For a specific set of voltage parameters (e.g., pulse number, frequency, duration), the effect that the electric field has on a cell depends on the voltage gradients that develop across the individual cell [4]. A voltage gradient, depending on its magnitude, can have one of three effects on the cell membrane: reversible permeation, in which the cell membrane reseals after the application of the pulse, irreversible permeation (i.e., cell death—in which the cell membrane does not reseal), or no change in the cell membrane. Electroporation can be used with any type of macromolecule, including drugs for cancer therapy or gene constructs for gene therapy, and is used with individual cells (in vitro) and with cells in the human body (in vivo). When electroporation is used in vivo, electrodes are strategically placed in the tissue and high-voltage electrical pulses are applied in such a way to produce voltage gradients that temporarily permeate the cells of a predetermined area. This facilitates the penetration of extracellular macromolecules such as drugs or gene constructs into the cells of the electroporated area [1], [5], [6]. A recent extensive book in the field of tissue electroporation is [7].
