Electroporation of archaeal lipid membranes using MD simulations.
Molecular dynamics (MD) simulations were used to investigate the electroporation of archaeal lipid bilayers when subjected to high transmembrane voltages induced by a charge imbalance, mimicking therefore millisecond electric pulse experiments. The structural characteristics of the bilayer, a 9:91 mol% 2,3-di-O-sesterterpanyl-sn-glicerol-1-phospho-myo-inositol (AI) and 2,3-di-O-sesterterpanyl-sn-glicerol-1-phospho-1'(2'-O-α-D-glucosyl)-myo-inositol (AGI) were compared to small angle X-ray scattering data. A rather good agreement of the electron density profiles at temperatures of 298 and 343 K was found assessing therefore the validity of the protocols and force fields used in simulations. Compared to dipalmitoyl-phosphatidylcholine (DPPC), the electroporation threshold for the bilayer was found to increase from ~2 V to 4.3 V at 323 K, and to 5.2 V at 298 K. Comparing the electroporation thresholds of the archaeal lipids to those of simple diphytanoyl-phosphatidylcholine (DPhPC) bilayers (2.5 V at 323 K) allowed one to trace back the stability of the membranes to the structure of their lipid head groups. Addition of DPPC in amounts of 50 mol% to the archaeal lipid bilayers decreases their stability and lowers the electroporation thresholds to 3.8 V and 4.1 V at respectively 323 and 298 K. The present study therefore shows how membrane compositions can be selected to cover a wide range of responses to electric stimuli. This provides new routes for the design of liposomes that can be efficiently used as drug delivery carriers, as the selection of their composition allows one to tune in their electroporation threshold for subsequent release of their load.
University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, SI-1000 Ljubljana, Slovenia. Electronic address: andraz.polak@fe.uni-lj.si.
Andraž
A
Polak
Université de Lorraine, UMR 7565, F-54506 Vandoeuvre-lés-Nancy, France; CNRS, UMR 7565, F-54506 Vandoeuvre-lés-Nancy, France. Electronic address: mounir.tarek@univ-lorraine.fr.
Mounir
M
Tarek
University of Ljubljana, Faculty of Chemistry and Chemical Technology, Aškerčeva c. 5, SI-1000 Ljubljana, Slovenia. Electronic address: matija.tomsic@fkkt.uni-lj.si.
Matija
M
Tomšič
University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia. Electronic address: janez.valant@bf.uni-lj.si.
Janez
J
Valant
University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia. Electronic address: natasa.poklar@bf.uni-lj.si.
Nataša Poklar
NP
Ulrih
University of Ljubljana, Faculty of Chemistry and Chemical Technology, Aškerčeva c. 5, SI-1000 Ljubljana, Slovenia. Electronic address: andrej.jamnik@fkkt.uni-lj.si.
Andrej
A
Jamnik
University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, SI-1000 Ljubljana, Slovenia. Electronic address: peter.kramar@fe.uni-lj.si.
Peter
P
Kramar
University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, SI-1000 Ljubljana, Slovenia. Electronic address: damijan.miklavcic@fe.uni-lj.si.
Damijan
D
Miklavčič
D001105:Archaea / Q000166:cytology*; D025802:Electric Capacitance; D018274:Electroporation; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism*; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D016062:Porosity; D053838:Scattering, Small Angle; D053835:Unilamellar Liposomes / Q000737:chemistry / Q000378:metabolism; D014961:X-Ray Diffraction
D008051:Lipid Bilayers; D053835:Unilamellar Liposomes
Aeropyrum pernix; Charge imbalance; Lipid bilayers; Transmembrane voltage; X-ray scattering