Electroporation of heterogeneous lipid membranes.

Electroporation is the basis for the transfection of genetic material and for drug delivery to cells, including electrochemotherapy for cancer. By means of molecular dynamics many aspects of membrane electroporation have been unveiled at the molecular detail in simple, homogeneous, lipid bilayers. However, the correspondence of these findings \with the process happening in cell membranes requires, at least, the consideration of laterally structured membranes. Here, I present a systematic molecular dynamics study of bilayers composed of different liquid-ordered and liquid-disordered lipid phases subjected to a transversal electric field. The simulations reveal two significant results. First, the electric field mainly affects the properties of the disordered phases, so that electroporation takes place in these membrane regions. Second, the smaller the disordered domains are, the faster they become electroporated. These findings may have a relevant significance in the experimental application of cell electroporation in vivo since it implies that electro-induced and pore-mediated transport processes occur in particularly small disordered domains of the plasma membrane, thus locally affecting only specific regions of the cell.