Phospholipid molecules exhibit amphiphilic properties and therefore they aggregate either in their crystalline state or in polar solvents into ordered structures with typical lyotropic liquid crystalline symmetries (de Gennes, 1974). At high lipid concentrations in water these are predominantly lamellar phases (Luzzati, 1968), while in aqueous solutions phospholipid molecules normally form self...

Starburst dendrimers (SBDs) of different generations (size) and level of protonations of their surface amino groups and solutions of dimyristoylphosphatidylcholine (DMPC) vesicles were analyzed, both separately and in mixtures of the two components, by negative-staining transmission electron microscopy (TEM), dynamic light scattering (DLS), and, mainly, by computer-aided continuous wave (CW)and...

To investigate the molecular organization and phase behavior of physiologic lipid mixtures that contain either newly synthesized pseudoceramide or type III synthetic ceramide, various analytical techniques were used. The phase transition temperatures detected in differential scanning calorimetry analysis were 51.19 and 50.52 for the pseudoceramide-containing physiologic lipid mixture and synthe...

Extrusion of multilamellar vesicles under moderate pressures through filters of defined pore size is a convenient method for generation of large unilamellar vesicles of variable size (Hope et al, (1986) Chem. Phys. Lipids 40, 89-108). To date, this technique has been applied primarily to unsaturated phosphoUpids in the liquid-crystalline state. In this work we extend this procedure to include s...

Fusion of multilamellar phospholipid vesicles with planar phospholipid bilayer membranes was monitored by the rate of appearance in the planar membrane of an intrinsic membrane protein present in the vesicle membranes. An essential requirement for fusion is an osmotic gradient across the planar membrane, with the cis side (the side containing the vesicles) hyperosmotic to the opposite (trans) s...

The amount of amphotericin B (AmB) associated with cultured murine macrophage-like J774 cells, after incubation with various AmB lipid formulations, was determined by absorption spectroscopy. Large, negatively charged, AmB-containing, multilamellar vesicles and small cholesteryl sulphate-AmB complexes both enhanced the amount of AmB associated with J774 cells at 37 degrees C (up to 500-fold the...

OBJECTIVES To investigate the efficacy of a single i.v. dose of clodronate encapsulated within small unilamellar vesicles in suppressing joint inflammation and the histological progression of rat antigen-induced arthritis (AIA). METHODS Rats with AIA received a single i.v. injection of 20 mg of clodronate encapsulated within small unilamellar vesicles (SUVc) or larger multilamellar vesicles (...

This paper reports a morphological transition of the spherical colloidal structures of the sodium dodecyl sulfate-polyethylene-b-polyethylene glycol (SDS-PE-b-PEG) complex and anionic micelle (SDS) to "rod-shaped" colloidal structures induced by a charge transfer dye, 1,8-naphthalimide (NAPMD) (forms anions in aqueous solution by intermolecular charge transfer). The distinct steady-state result...

Membrane structures of the mixtures of ganglioside G(M1) and endosome specific lipid, bis (monoacylglycero) phosphate (BMP, also known as lysobisphosphatidic acid) were examined at various pH conditions by freeze-fracture electron microscopy and small-angle x-ray scattering. At pH 8.5-6.5, a G(M1)/BMP (1:1 mol/mol) mixture formed small vesicular aggregates, whereas the mixture formed closely pa...

Model membrane systems are used extensively in all aspects of membrane research, and freeze-fracture is the preeminent procedure for directly visualizing local structure in these lipid dispersions. Here we describe in detail the formation of liposomes and how freeze-fracture is routinely employed as a complementary technique to biophysical and biochemical procedures in the characterization of m...