Quantitative study of molecular transport due to electroporation: uptake of bovine serum albumin by erythrocyte ghosts.

Electroporation is believed to involve the creation of aqueous pathways in lipid bilayer membranes by transient elevation of the transmembrane voltage to approximately 1 V. Here, results are presented for a quantitative study of the number of bovine serum albumin (BSA) molecules transported into erythrocyte ghosts caused by electroportion. 1) Uptake of BSA was found to plateau at high field strength. However, this was not necessarily an absolute maximum in transport. Instead, it represented the maximum effect of increasing field strength for a particular pulse protocol. 2) Maximum uptake under any conditions used in this study corresponded to approximately one-fourth of apparent equilibrium with the external solution. 3) Multiple and longer pulses each increased uptake of BSA, where the total time integral of field strength correlated with uptake, independent of inter-pulse spacing. 4) Pre-pulse adsorption of BSA to ghost membranes appears to have increased transport. 5) Most transport of BSA probably occurred by electrically driven transport during pulses; post-pulse uptake occurred, but to a much lesser extent. Finally, approaches to increasing transport are discussed.