title: Study of the Impact of Polyanions on the Formation of Lipid Bilayers on Top of Polyelectrolyte Multilayers with Poly(allylamine hydrochloride) as the Top Layer.
abstract: The impact of polyanions on the formation of lipid bilayers on top of polyelectrolyte multilayers (PEMs) with poly(allylamine hydrochloride) (PAH) as the top layer is studied for the deposition of vesicles of mixed lipid composition, 50:50 molar ratio of zwitterionic 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and negatively charged 1,2-dioleoyl-sn-glycero-3-phospho-l-serine (DOPS). PEMs are assembled with polystyrene sulfonate (PSS), poly(acrylic acid) (PAA), and alginic acid sodium salt (Alg) as polyanions. The assembly of the vesicles on the PEMs is followed by means of the quartz crystal microbalance with dissipation. Fluorescence recovery after photobleaching measurements are applied to evaluate bilayer formation. Whereas a bilayer is formed on top of PAH/PSS multilayers, the vesicles are adsorbed on top of PAH/Alg and PAH/PAA multilayers, remaining unruptured or only partially fused. The influence of the surface composition of the PEM and of the bulk properties of the film are analyzed. The phosphate ions present in phosphate-buffered saline (PBS) play a fundamental role in bilayer formation on top of PAH/PSS as they complex with PAH and render the surface potential close to zero. For PAH/PAA and PAH/Alg, PBS renders the surface negative. X-ray photoelectron spectroscopy shows that the dibasic phosphate ions from PBS complex preferentially with PAH in PAH/PAA and PAH/Alg multilayers, whereas monobasic phosphates complex with PAH in PAH/PSS. An explanation for the absence of bilayer formation on PAH/PAA and PAH/Alg is given on the basis of the different affinities of phosphate ions for PAH in combination with the different polyanions.
authors.affiliation: Soft Matter Nanotechnology Group, CIC biomaGUNE , Paseo Miramón 182 C, 20009 San Sebastian, Guipuzcoa, Spain.
authors.forename: Eleftheria
authors.initials: E
authors.lastname: Diamanti
authors.affiliation: Soft Matter Nanotechnology Group, CIC biomaGUNE , Paseo Miramón 182 C, 20009 San Sebastian, Guipuzcoa, Spain.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Andreozzi
authors.affiliation: Department of Chemical and Biological Engineering, University of Colorado Boulder , 3415 Colorado Avenue, Boulder, 80309-0596 Colorado, United States.
authors.forename: Christopher
authors.initials: C
authors.lastname: Kirby
authors.affiliation: Departamento de Materiales Avanzados, Centro de Investigación en Química Aplicada , Blvd. Enrique Reyna Hermosillo No.140, 25250 Saltillo, Coahuila, México.
authors.forename: Ramiro
authors.initials: R
authors.lastname: Anguiano
authors.affiliation: Soft Matter Nanotechnology Group, CIC biomaGUNE , Paseo Miramón 182 C, 20009 San Sebastian, Guipuzcoa, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Yate
authors.affiliation: Department of Chemical and Biological Engineering, University of Colorado Boulder , 3415 Colorado Avenue, Boulder, 80309-0596 Colorado, United States.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Heinz
authors.affiliation: Department of Chemical and Biological Engineering, University of Colorado Boulder , 3415 Colorado Avenue, Boulder, 80309-0596 Colorado, United States.|Departamento de Materiales Avanzados, Centro de Investigación en Química Aplicada , Blvd. Enrique Reyna Hermosillo No.140, 25250 Saltillo, Coahuila, México.
authors.forename: Ronald F
authors.initials: RF
authors.lastname: Ziolo
authors.affiliation: Institute of Biophysics and Medical Physics, Faculty of Medicine, University of Leipzig , 04107 Leipzig, Germany.
authors.forename: Edwin
authors.initials: E
authors.lastname: Donath
authors.affiliation: Soft Matter Nanotechnology Group, CIC biomaGUNE , Paseo Miramón 182 C, 20009 San Sebastian, Guipuzcoa, Spain.
authors.forename: Sergio Enrique
authors.identifier: 0000-0002-7174-1960
authors.initials: SE
authors.lastname: Moya