title: A molecular dynamic study of cholesterol rich lipid membranes: comparison of electroporation protocols.
abstract: We report on a molecular dynamics (MD) simulation study of the electroporation of lipid bilayers at different cholesterol contents using protocols mimicking "traditional" electroporation, i.e. low intensity millisecond pulses (msEP), and high intensity nanosecond electric pulses (nsEP). The results show that addition of cholesterol in concentrations of lipid:sterol ranging from 20 to 50 mol% enhances substantially the membrane cohesion, which is manifested by an increase of the electroporation threshold (U(thr)). This increase is steady in the case of the nsEP protocol, reaching roughly a factor 2 in the 50 mol% samples. In contrast, for the msEP protocol, U(thr) increases by 50% upon addition of 30 mol% cholesterol then levels off. Furthermore, pores formed under msEP are found to possess morphologies much different from the usually reported hydrophilic "electropores" encountered under the nsEP protocol, which may have profound consequences on the transport properties of "electroporated" membranes. Hence, this study reveals that cell membrane models containing the ubiquitous cholesterol component respond quite differently to the two electroporation techniques, in contrast to what has been found for simple zwitterionic bilayers.
authors.affiliation: Dipartimento di Ingegneria Informatica, Elettronica e Telecomunicazioni (D.I.E.T), University of Rome "La Sapienza", Roma, Italy; Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, 00161 Roma, Italy; Université de Lorraine, Theory, Modeling and Simulation Group, UMR 7565, F-54506 Vandoeuvre-lès-Nancy, France.
authors.forename: M
authors.initials: M
authors.lastname: Casciola
authors.affiliation: Université de Lorraine, Theory, Modeling and Simulation Group, UMR 7565, F-54506 Vandoeuvre-lès-Nancy, France.
authors.forename: D
authors.initials: D
authors.lastname: Bonhenry
authors.affiliation: Dipartimento di Ingegneria Informatica, Elettronica e Telecomunicazioni (D.I.E.T), University of Rome "La Sapienza", Roma, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Liberti
authors.affiliation: Dipartimento di Ingegneria Informatica, Elettronica e Telecomunicazioni (D.I.E.T), University of Rome "La Sapienza", Roma, Italy; Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, 00161 Roma, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Apollonio
authors.affiliation: Université de Lorraine, Theory, Modeling and Simulation Group, UMR 7565, F-54506 Vandoeuvre-lès-Nancy, France; CNRS, Theory, Modeling and Simulation Group, UMR 7565, F-54506 Vandoeuvre-lès-Nancy, France. Electronic address: mounir.tarek@univ-lorraine.fr.
authors.forename: M
authors.initials: M
authors.lastname: Tarek
mesh_terms: D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism*; D002784:Cholesterol / Q000737:chemistry / Q000378:metabolism*; D018274:Electroporation / Q000379:methods*; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism*; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D010713:Phosphatidylcholines / Q000378:metabolism; D013997:Time Factors
chemical_list: D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D002784:Cholesterol; C028694:1-palmitoyl-2-oleoylphosphatidylcholine
keywords: Electric fields; Molecular modeling; Nanopore morphologies; Permeabilization; lipid bilayers