title: Non-phospholipid fusogenic liposomes.
abstract: We have demonstrated the capacity of non-phospholipid liposomes composed primarily of dioxyethylene acyl ethers and cholesterol to fuse with membranes composed primarily of phospholipid. Phase-contrast microscopy, freeze-fracture electron microscopy and a macromolecular probe indicate that these non-phospholipid liposomes can fuse with the plasma membranes of erythrocytes and fibroblasts. Furthermore, fluorescence probe experiments have demonstrated fusion between phosphatidylcholine liposomes and non-phospholipid liposomes. Mixing of internal contents was shown by a terbium/dipicolinate assay. Mixing of membrane lipid components was demonstrated by measuring (i) fluorescence resonance energy transfer between N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)phosphatidylethanolamine and N-(lissamine rhodamine B sulfonyl)phosphatidylethanolamine, after phosphatidylcholine liposomes were mixed with non-phospholipid liposomes, and (ii) reduced concentration quenching of rhodaminephosphatidylethanolamine and octadecylrhodamine incorporated into phosphatidylcholine liposomes after mixing with the non-phospholipid liposomes. The degree of apparent fusion reported by the different probe techniques ranged from 25% to 64%.
authors.affiliation: URA CNRS 1856, Dynamique Moléculaire des Interactions Membranaires, Université Montpellier II, Place Eugène Bataillon, Montpellier, France.
authors.forename: M
authors.initials: M
authors.lastname: El Baraka
authors.forename: E I
authors.initials: EI
authors.lastname: Pécheur
authors.forename: D F
authors.initials: DF
authors.lastname: Wallach
authors.forename: J R
authors.initials: JR
authors.lastname: Philippot
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002462:Cell Membrane / Q000502:physiology* / Q000648:ultrastructure; D002784:Cholesterol; D003902:Detergents; D004337:Drug Carriers; D004910:Erythrocyte Membrane / Q000502:physiology* / Q000648:ultrastructure; D005019:Ethyl Ethers; D005347:Fibroblasts / Q000502:physiology; D005456:Fluorescent Dyes; D005614:Freeze Fracturing; D006735:Horseradish Peroxidase / Q000008:administration & dosage; D006801:Humans; D007700:Kinetics; D008081:Liposomes; D008561:Membrane Fusion; D051379:Mice; D008854:Microscopy, Electron; D008858:Microscopy, Phase-Contrast; D010743:Phospholipids; D013329:Structure-Activity Relationship
chemical_list: D003902:Detergents; D004337:Drug Carriers; D005019:Ethyl Ethers; D005456:Fluorescent Dyes; D008081:Liposomes; D010743:Phospholipids; D002784:Cholesterol; D006735:Horseradish Peroxidase