Measuring the potential energy barrier to lipid bilayer electroporation.
A hydrophobic pore that surmounts the energy barrier will convert to a toroidal pore. The applied transmembrane potential lowers the pore free energy. Electroporation is a common tool for gene transfection, tumour ablation, sterilization and drug delivery. Using experimental methods, we explore the temperature dependence of electropore formation in a model membrane system (droplet-interface bilayers), using optical single-channel recording to image the real-time gating of individual electropores. We investigate the influence of the agarose substrate on electropores formed in this system. Furthermore, by examining the temperature-dependent kinetics of pore opening and closure we are able to estimate a barrier to pore opening in 1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC) membranes to be 25.0 ± 8.3 kT, in agreement with previous predictions. Overall these measurements help support the toroidal model of membrane electroporation.
This article is part of the themed issue ‘Membrane pores: from structure and assembly, to medicine and technology’.