title: Physicochemical characterization of artificial nanoerythrosomes derived from erythrocyte ghost membranes.
abstract: Colloidal stabile nanoerythrosomes with 200 nm average diameter were formed from hemoglobin-free erythrocyte ghost membrane via sonication and membrane extrusion. The incorporation of extra lipid (1,2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC), added to the sonicated ghosts, caused significant changes in the thermotropic character of the original membranes. As a result of the increased DPPC ratio the chain melting of the hydrated DPPC system and the characteristic small angle X-ray scattering (SAXS) of the lipid bilayers appeared. Significant morphological changes were followed by transmission electron microscopy combined with freeze fracture method (FF-TEM). After the ultrasonic treatment the large entities of erythrocyte ghosts transformed into nearly spherical nanoerythrosomes with diameters between 100 and 300 nm and at the same time a great number of 10-30 nm large membrane proteins or protein clusters were dispersed in the aqueous medium. The infrared spectroscopy (FT-IR) pointed out, that the sonication did not cause changes in the secondary structures of the membrane proteins under our preparation conditions. About fivefold of extra lipid--compared to the lipid content of the original membrane--caused homogeneous dispersion of nanoerythrosomes however the shape of the vesicles was not uniform. After the addition of about tenfold of DPPC, monoform and monodisperse nanoerythrosomes became typical. The outer surfaces of these roughly spherical objects were frequently polygonal, consisting of a net of pentagons and hexagons.
authors.affiliation: Research Group of Biological Nanochemistry, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1117 Budapest, Magyar tudósok körútja 2, Hungary.
authors.forename: Róbert
authors.initials: R
authors.lastname: Deák
authors.affiliation: Research Group of Biological Nanochemistry, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1117 Budapest, Magyar tudósok körútja 2, Hungary.
authors.forename: Judith
authors.initials: J
authors.lastname: Mihály
authors.affiliation: Research Group of Biological Nanochemistry, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1117 Budapest, Magyar tudósok körútja 2, Hungary.
authors.forename: Imola Cs
authors.initials: IC
authors.lastname: Szigyártó
authors.affiliation: Research Group of Biological Nanochemistry, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1117 Budapest, Magyar tudósok körútja 2, Hungary.
authors.forename: András
authors.initials: A
authors.lastname: Wacha
authors.affiliation: Central Laboratory of the National Institute of Rheumatology and Physiotherapy, 1023 Budapest, Frankel Leó u. 25-29, Hungary.
authors.forename: Gábor
authors.initials: G
authors.lastname: Lelkes
authors.affiliation: Research Group of Biological Nanochemistry, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1117 Budapest, Magyar tudósok körútja 2, Hungary. Electronic address: bota.attila@ttk.mta.hu.
authors.forename: Attila
authors.initials: A
authors.lastname: Bóta
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D004910:Erythrocyte Membrane / Q000737:chemistry*; D005614:Freeze Fracturing; D006801:Humans; D008051:Lipid Bilayers; D008565:Membrane Proteins / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011510:Proteolipids / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D014465:Ultrasonics
chemical_list: D008051:Lipid Bilayers; D008565:Membrane Proteins; D011510:Proteolipids; C020485:proteoliposomes; D015060:1,2-Dipalmitoylphosphatidylcholine
keywords: Erythrocyte; Freeze fracture TEM; Infrared spectroscopy; Nanoerythrosomes; Protein to lipid ratio; Small angle X-ray scattering (SAXS); Vesicles