High Resistivity Lipid Bilayers Assembled on Polyelectrolyte Multilayer Cushions: An Impedance Study.
Supported membranes on top of polymer cushions are interesting models of biomembranes as cell membranes are supported on a polymer network of proteins and sugars. In this work lipid vesicles formed by a mixture of 30% 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 70% 1,2-dioleoyl-sn-glycero-3-phospho-l-serine (DOPS) are assembled on top of a polyelectrolyte multilayer (PEM) cushion of poly(allylamine hydrochloride) (PAH) and poly(styrene sodium sulfonate) (PSS). The assembly results in the formation of a bilayer on top of the PEM as proven by means of the quartz crystal microbalance with dissipation technique (QCM-D) and by cryo-transmission electron microscopy (cryo-TEM). The electrical properties of the bilayer are studied by electrochemical impedance spectroscopy (EIS). The bilayer supported on the PEMs shows a high resistance, on the order of 10(7) Ω cm(2), which is indicative of a continuous, dense bilayer. Such resistance is comparable with the resistance of black lipid membranes. This is the first time that such values are obtained for lipid bilayers supported on PEMs. The assembly of polyelectrolytes on top of a lipid bilayer decreases the resistance of the bilayer up to 2 orders of magnitude. The assembly of the polyelectrolytes on the lipids induces defects or pores in the bilayer which in turn prompts a decrease in the measured resistance.
Soft Matter Nanotechnology Group, CIC biomaGUNE, Paseo Miramón 182 C, 20009 San Sebastián, Guipúzcoa, Spain.
Eleftheria
E
Diamanti
Soft Matter Nanotechnology Group, CIC biomaGUNE, Paseo Miramón 182 C, 20009 San Sebastián, Guipúzcoa, Spain.
Danijela
D
Gregurec
Instituto de Investigaciones, Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de la Plata, CONICET , Sucursal 4-C.C.16, 1900 La Plata, Argentina.
María José
MJ
Rodríguez-Presa
Instituto de Investigaciones, Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de la Plata, CONICET , Sucursal 4-C.C.16, 1900 La Plata, Argentina.|Area Electroquímica, Facultad de Ingeniería, Universidad Nacional de La Plata , calle 1 y 47, 1900 La Plata, Argentina.
Claudio A
CA
Gervasi
Instituto de Investigaciones, Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de la Plata, CONICET , Sucursal 4-C.C.16, 1900 La Plata, Argentina.
Omar
O
Azzaroni
Soft Matter Nanotechnology Group, CIC biomaGUNE, Paseo Miramón 182 C, 20009 San Sebastián, Guipúzcoa, Spain.
Sergio E
SE
Moya
D002462:Cell Membrane; D017097:Electric Impedance; D008051:Lipid Bilayers / Q000737:chemistry*; D000071228:Polyelectrolytes / Q000737:chemistry*; D058525:Quartz Crystal Microbalance Techniques
D008051:Lipid Bilayers; D000071228:Polyelectrolytes