Study on liposomes by capillary electrophoresis

Wiedmer, Susanne Κ.; Hautala, Jari T.; Holopainen, Juha M.; Kinnunen, Paavo K.J.; Riekkola, Marja‐Liisa

doi:10.1002/1522-2683(200105)22:7<1305::aid-elps1305>3.0.co;2-q

Cited by 82 publications

(56 citation statements)

References 25 publications

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“…With about 30% anionic lipid a flattening of the curve is seen such that the liposomes were almost saturated with negative charges (44). This same flattening after 30% PG can be seen with the zeta potential determinations here.…”

Section: Effect Of Liposome Compositionmentioning

confidence: 99%

Interaction of Basic Drugs with Lipid Bilayers Using Liposome Electrokinetic Chromatography

Carrozzino

Khaledi

2004

Pharm Res

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These studies demonstrate the overall buffer ionic strength at a given pH is more important than buffer type and concentration. The interaction of positively charged drugs with charged lipid bilayer membranes is selectively influenced by the pKa of the drug. Liposomes are more biologically relevant in vitro models for cell membranes than octanol, and LEKC provides a unique combination of advantages for rapid screening of drug-membrane interactions.

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Section: Effect Of Liposome Compositionmentioning

confidence: 99%

Interaction of Basic Drugs with Lipid Bilayers Using Liposome Electrokinetic Chromatography

Carrozzino

Khaledi

2004

Pharm Res

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“…The bilayer structure makes vesicles attractive for use as model membranes, drug delivery devices, and microreactors [1][2][3]. Liposomes have been investigated for use as a pseudostationary phase in electrokinetic chromatography (EKC) [4][5][6][7]. Unfortunately, the unilamellar state is not the most thermodynamically stable form of the phospholipid aggregates.…”

Section: Introductionmentioning

confidence: 99%

Effect of class I and II organic modifiers on retention and selectivity in vesicle electrokinetic chromatography

Pascoe

Foley

2002

Electrophoresis

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Vesicles are large aggregates of surfactant monomers consisting of a spherical bilayer surrounding an internal cavity of solvent. The bilayer structure allows vesicles to be attractive models for the study of various transmembrane and binding processes. The use of thermodynamically stable vesicles (TSV) formed from oppositely charged surfactants for use as a pseudostationary phase in electrokinetic chromatography (EKC) was first accomplished using dodecyltrimethylammonium bromide and sodium dodecyl sulfate (DTAB/SDS). Surfactant vesicles have demonstrated enhanced separation characteristics compared to conventional micelles in EKC, although only investigated in aqueous media. Organic modifiers have been widely studied and used in EKC to enhance separation conditions. In this study, vesicles formed from cetyltrimethylammonium bromide and sodium octyl sulfate (CTAB/SOS) were investigated in the presence of "class I and II" organic modifiers. Electrophoretic and chromatographic parameters were examined as well as linear solvation energy relationship analysis (LSER) to characterize the effects of the modifiers on retention and selectivity in EKC. LSER analysis is a useful way to quantitatively investigate solute/solvent interactions responsible for retention and selectivity.

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“…The resulting mixture was evaporated to dryness under a stream of nitrogen, and traces of solvent were removed by evacuation under reduced pressure for 24 h. The lipid residues were hydrated in the indicated buffer at 60°C to yield MLVs with a lipid concentration of 3-4 mM, and the vesicles were maintained at this temperature for 60 min with subsequent vortexing. The resulting dispersion was processed to LUVs by extrusion 19 times through Millipore (Bedford, MA, USA) 0.1 µm pore-size polycarbonate filters using a LiposoFast extruder, essentially as described previously [16]. The prepared liposome solutions were stored in a refrigerator.…”

Section: Liposome Preparationmentioning

confidence: 99%

“…Liposomes have been used as a dispersed phase [12,13,14,15,16,17] and for coating of capillaries [11,18,19]. Cunliffe et al [11] used zwitterionic phospholipids and calcium in the coating process and reported that without calcium the coating time was prolonged almost 20-fold [11].…”

Section: Introductionmentioning

confidence: 99%

Anionic liposomes in capillary electrophoresis: Effect of calcium on 1-palmitoyl-2-oleyl- sn -glycero-3-phosphatidylcholine / phosphatidylserine-coating in silica capillaries

Hautala¹,

Wiedmer

Riekkola

2004

Analytical and Bioanalytical Chemistry

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The effect of calcium on phospholipid coatings in fused silica capillaries used in capillary electrophoresis was studied. The anionic liposomes used for the coating consisted of 3 mM 1-palmitoyl-2-oleyl- sn-glycero-3-phosphatidylcholine and phosphatidylserine in the ratio 80/20 mol%. Coating was performed as part of the preconditioning, and the capillaries could be used for several runs without the need for liposomes in the background electrolyte solution or for liposome rinses between runs. Phospholipids could easily be flushed away by rinsing with a chloroform-methanol (2:1 v/v) mixture, which made it possible to recoat and reuse the capillaries. A calcium:phospholipid ratio of approximately 3 gave the most stable coating. The stability of the coating and success of the coating procedure were studied by measuring the electroosmotic flow and by separating uncharged steroids, which were used as model compounds. Many parameters that affect the coating, such as preconditioning (with different acids and bases), buffer, temperature during coating, and the physical structures of liposomes, were studied, with and without calcium in the liposome solution. The separation of steroids was improved and was less dependent on coating conditions when calcium was present during the coating. Capillaries optimally coated with anionic phospholipids were applied in the separation of phenols.

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Study on liposomes by capillary electrophoresis

Cited by 82 publications

References 25 publications

Interaction of Basic Drugs with Lipid Bilayers Using Liposome Electrokinetic Chromatography

Interaction of Basic Drugs with Lipid Bilayers Using Liposome Electrokinetic Chromatography

Effect of class I and II organic modifiers on retention and selectivity in vesicle electrokinetic chromatography

Anionic liposomes in capillary electrophoresis: Effect of calcium on 1-palmitoyl-2-oleyl- sn -glycero-3-phosphatidylcholine / phosphatidylserine-coating in silica capillaries

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