Phospholipids and liposomes in liquid chromatographic and capillary electromigration techniques

Wiedmer, Susanne Κ.; Riekkola, Marja‐Liisa; Jussila, Minttu S.

doi:10.1016/j.trac.2004.03.001

Cited by 74 publications

(52 citation statements)

References 94 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…phospholipid vesicles) are utilized in many LC and CE techniques, either as coatings or (drug) carriers [1][2][3][4]. Lipid aggregates (liposomes, micelles, bicelles, and discoidal micelles) have been used as models of the structure and function of mammalian cell membranes, for instance, in drug partitioning studies [5].…”

Section: Introductionmentioning

confidence: 99%

Dynamic coating of SU‐8 microfluidic chips with phospholipid disks

et al. 2010

Self Cite

View full text Add to dashboard Cite

In this work, PEG-stabilized phosphatidylcholine lipid aggregates (disks), mimicking mammalian cell membranes, were introduced as a new biofouling resistant coating for SU-8 polymer microchannels. A rapid and simple method was developed for immobilization of PEGylated phosphatidylcholine disks in microchannels. Microfluidic chips made from SU-8, PDMS, or glass were dynamically coated with the PEGylated disks followed by characterization of their surface chemistry before and after coating. On the basis of the observed changes in EOF and nonspecific protein adsorption, the affinity of the PEGylated disks was shown to be particularly strong toward SU-8. The PEG-lipid coating enabled permanent change in EOF in SU-8 microchannels with an initial value of 4.5 x 10(-8) m(2) V(-1) s(-1), decreasing to 2.1 x 10(-8) m(2) V(-1) s(-1) (immediately after modification), and, eventually, to 1.5 x 10(-8) m(2) V(-1) s(-1) (7 days after modification) for 9 mM sodium borate (pH 10.5) as BGE. As determined by the Wilhelmy plate measurements and microchip-CE analysis of BSA, the PEG-lipid coating also enabled efficient biofouling shield against protein adsorption, similar to that of low amounts of SDS (3.5 mM) or Tween-20 (80 microM) as buffer additives. These results suggest that dynamically attached PEG-lipid aggregates provide stable, biomimicking surface modification that efficiently reduces biofouling on SU-8.

show abstract

Section: Introductionmentioning

confidence: 99%

Dynamic coating of SU‐8 microfluidic chips with phospholipid disks

et al. 2010

Self Cite

View full text Add to dashboard Cite

show abstract

“…For this reason, they can be analyzed by CE, and they proved useful as anionic pseudostationary phases in EKC ( ; for recent reviews see [23,24]. It was found that, besides the pH, the kind of the electrolytes [6,25] and its ionic strength [5,18], and the preparation procedure of the vesicles influences the electrophoretic properties of the particles [23,26]. If their electrophoretic mobility is affected upon attachment of ligands, this change can be used to assess, or even quantify, the interaction in a form of ACE.…”

Section: Introductionmentioning

confidence: 99%

Capillary electrophoresis of liposomes functionalized for protein binding

et al. 2006

View full text Add to dashboard Cite

CE enabled assessing the attachment of hexa-histidine-tagged proteins to functionalized phospholipid liposomes. The liposomes were made of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, phosphatidyl-ethanolamine, cholesterol and distearoyl-glycero-3-phosphoethanolamine-N-methoxy(polyethylene glycol) in a molar ratio of 29:26:40:5. The unilamellar vesicles, which had an average diameter of 170 nm, were labelled by inclusion of FITC-dextran for fluorescence detection. CE was carried out in poly(vinyl alcohol) (PVA)-coated capillaries at 25 degrees C with a BGE consisting of Tris-HCl (50 mM, pH 8.0). For conjugation of the liposomes with the proteins (soluble synthetic receptor fragments with molecular mass of 60 and 70 kDa, respectively), Ni(2+) was implanted into the vesicle surface by an anchor lipid containing a nitrilotriacetate acid (NTA) group as complexation agent for the metal ions. The difference in surface charge enabled the separation of the different species of interest by CE: plain vesicles, vesicles functionalised with Ni-NTA, vesicle-protein complexes and the species formed upon removal of the Ni-ions by complexation with EDTA. Loss of the Ni-ions resulted in the release of the proteins and the reappearance of the plain Ni-free NTA-liposome species in the electropherograms.

show abstract

“…During the 1990s, liquid chromatography became a well-established method for the study of membraneanalyte interactions. Today, there are basically two types of liquid chromatographic stationary phases containing phospholipids or liposomes: immobilized artificial membrane phases and immobilized liposome chromatographic phases [1]. In general, immobilized artificial membrane phases are highly stable and commercially available, whilst there are only a few commercial immobilized liposome chromatographic phases with favorable characteristics.…”

Section: Introductionmentioning

confidence: 99%

Piperazine-based buffers for liposome coating of capillaries for electrophoresis

et al. 2005

Self Cite

View full text Add to dashboard Cite

Anionic liposomes can be coated on fused-silica capillaries for electrophoresis in the presence of N-(hydroxyethyl)piperazine-N'-(2-ethanesulfonic acid) (HEPES) as background electrolyte (BGE) solution. In this work, the interaction of various compounds with zwitterionic and anionic phospholipid coatings was studied with HEPES at pH 7.4 as BGE solution. The chromatographic and electrophoretic behavior of three test sample solutions (anionic, cationic, and neutral) was investigated for evaluation of the phospholipid coatings. Our results show that hydrophobic interactions between analytes and the phospholipid coating are important for the migration of charged analytes. In addition, the performances of other piperazine-based buffers, i.e., N-(2-hydroxyethyl)piperazine-N'-(2-hydroxypropanesulfonic acid), piperazine-N,N'-bis(2-ethanesulfonic acid), and piperazine-N,N'-bis(hydroxypropane sulfonic acid), at pH 7.4, as liposome solvent and BGE solution were evaluated and compared with the performance of HEPES at pH 7.4. The anionic liposome solution comprised 80/20 mol% phosphatidylcholine/phosphatidylserine. A simple test solution was selected and the chromatographic and electrophoretic migration behavior of the analytes was evaluated. The results show that, in addition to HEPES, other piperazine-based buffers at pH 7.4 are suitable for coating of fused-silica capillaries with anionic liposomes.

show abstract

Phospholipids and liposomes in liquid chromatographic and capillary electromigration techniques

Cited by 74 publications

References 94 publications

Dynamic coating of SU‐8 microfluidic chips with phospholipid disks

Dynamic coating of SU‐8 microfluidic chips with phospholipid disks

Capillary electrophoresis of liposomes functionalized for protein binding

Piperazine-based buffers for liposome coating of capillaries for electrophoresis

Contact Info

Product

Resources

About