title: Existence of hybrid structures in cationic liposome/DNA complexes revealed by their interaction with plasma proteins.
abstract: The self-assembling of cationic liposomes (CLs) and DNA can give rise to a variety of nanostructures and morphologies. Multilamellar complexes are made of DNA intercalated between opposing lipid bilayers, while clusters formed by intact vesicles may exist as 'beads-on-a-string' (i.e. CLs attached to a string of DNA). Precise knowledge of the structure and morphology of complexes is relevant in many biological important processes such as gene delivery. Here dynamic light scattering, zeta potential, synchrotron small angle X-ray scattering and one-dimensional polyacrylamide gel electrophoresis were performed to investigate the equilibrium structure, morphology and interactions with plasma proteins of lipoplexes made of the cationic lipid (3β-[N-(N',N'-dimethylaminoethane)-carbamoyl])-cholesterol (DC-Chol), the zwitterionic lipid dioleoylphosphatidylethanolamine (DOPE) and DNA. Results show that DC-Chol-DOPE/DNA complexes are multilamellar systems with DNA protected by cationic lipids. On the other hand, the 'protein corona' associated to lipoplexes after interaction with human plasma was found to be much richer in basic immunoglobulins gamma proteins (Ig-Gs) than that of pure lipid vesicles in the absence of DNA. According to the most recent evidences reported in the literature, this finding would suggest the existence of hybrid structures made of multilamellar complexes either stuck together by DNA or coexisting with DNA-loaded intact vesicles. Because surface properties of lipoplexes may determine their interaction with cells and tissues, these results may be important for predicting biological responses in vivo.
authors.affiliation: Institute of Biophysics and Nanosystems Research, Austrian Academy of Sciences, Schmiedlstraße 6, A-8042 Graz, Austria.
authors.forename: Heinz
authors.initials: H
authors.lastname: Amenitsch
authors.forename: Giulio
authors.initials: G
authors.lastname: Caracciolo
authors.forename: Patrizia
authors.initials: P
authors.lastname: Foglia
authors.forename: Valentina
authors.initials: V
authors.lastname: Fuscoletti
authors.forename: Piero
authors.initials: P
authors.lastname: Giansanti
authors.forename: Carlotta
authors.initials: C
authors.lastname: Marianecci
authors.forename: Daniela
authors.initials: D
authors.lastname: Pozzi
authors.forename: Aldo
authors.initials: A
authors.lastname: Laganà
mesh_terms: D001798:Blood Proteins / Q000378:metabolism*; D002412:Cations; D002784:Cholesterol / Q000737:chemistry / Q000378:metabolism; D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D057446:Hydrodynamics; D008027:Light; D008081:Liposomes / Q000737:chemistry* / Q000378:metabolism*; D010714:Phosphatidylethanolamines / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D053838:Scattering, Small Angle; D017356:Synchrotrons; D014961:X-Ray Diffraction
chemical_list: D001798:Blood Proteins; D002412:Cations; D008081:Liposomes; D010714:Phosphatidylethanolamines; C094877:dioleoyl phosphatidylethanolamine; D004247:DNA; D002784:Cholesterol