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Bilayer immobilization

Between bilayers immobilized onto substrates,55 bilayer-bilayer interaction measurements also sense interactions involving the substrate. After compensation for these features, measurements on all three systems pleasingly agree.56... [Pg.33]

Electrochemical permeability control of organic molecules by a bilayer-immobilized film containing redox sites has been reported 1 Bilayer-forming amphiphiles 37) and sodium poly(styrene sulfonate) (PSSNa) were mixed in water, and the resulting precipitates were dissolved in CHCI3 and cast on a Pt minigrid. The amphiphiles form extended lamellae parallel to the film plane in polyion complexes with polystyrene sulfonate (PSS ). The 57-PSS and the reduced 57-PSS" film showed phase transition temperatures T at 24° and 38 °C, respectively. When the 37 group... [Pg.191]

Charych et al. reported a direct colorimetric assay for the detection of influenza virus, using a polydiacetylene bilayer immobilized on a glass microscope slide and functionalized with sialic acid (the vims receptor molecule). Upon binding of the vims, a color change is visible to the naked eye, but could also be quantified by absorption spectroscopy. The authors demonstrated by physical characterization that the packing of the bilayer with bound vims was different from that without vims, resulting in a change of the optical properties of the polymer backbone. [Pg.124]

Ramsden J J 1998 Biomimetic protein immobilization using lipid bilayers Biosensors Bloelectronics 13 593—8... [Pg.2848]

Mira Josowicz, John Hartung, Janusz Kowalik, Christine Kranz, Jiri Janata, Ashwini Sinha, Kendra McCoy. J. Electrochem.Soc., (submitted), Electropolymerization of Bilayer with Phosphonic Acid Tethers for Immobilization of Biomolecules ... [Pg.296]

A very promising method, immobilized artificial membrane (IAM) chromatography, was developed by Pidgeon and co-workers [299-304,307], where silica resin was modified by covalent attachment of phospholipid-like groups to the surface. The retention parameters mimic the partitioning of drugs into phospholipid bilayers. The topic has been widely reviewed [47,298,307,309-311]. [Pg.54]

In the bulk of this chapter we will focus on the rapidly emerging new in vitro technology based on the use of immobilized artificial membranes, constructed of phospholipid bilayers supported on lipophilic filters. One objective is to complete the coverage of the components of the transport model explored in Chapter 2, by considering the method for determining the top curve (horizontal fine) in the plots... [Pg.117]

New developments in immobilization surfaces have lead to the use of SPR biosensors to monitor protein interactions with lipid surfaces and membrane-associated proteins. Commercially available (BIACORE) hydrophobic and lipophilic sensor surfaces have been designed to create stable membrane surfaces. It has been shown that the hydrophobic sensor surface can be used to form a lipid monolayer (Evans and MacKenzie, 1999). This monolayer surface can be used to monitor protein-lipid interactions. For example, a biosensor was used to examine binding of Src homology 2 domain to phosphoinositides within phospholipid bilayers (Surdo et al., 1999). In addition, a lipophilic sensor surface can be used to capture liposomes and form a lipid bilayer resembling a biological membrane. [Pg.103]

This encapsulation procedure gives the highest activity for the lipases. The lecithin/ amines mixture structuring the pore network leads to a suitable phospholipids bilayer-like environment, which avoids the necessity to create an interface by substrate assembly. Monduzzi and coworkers compared the activity of lipase that was immobilized on SBA-15 physically, or chemically with glutardialdehyde [200]. [Pg.141]

Mainly, three approaches have been used to immobilize the enzyme on transducer or electrode surface, single layer, bilayer, and sandwich configurations [69, 98], In some studies enzymes are covalently linked with sol-gel thin films [99], Sol-gel thin films are highly convenient for fast, large, and homogeneous electron transfer [17]. With an increase in gel thickness the signal decays and diffusion of analytes to biomolecule active site becomes difficult eventually these factors lead to poor response. By employing thin films various biosensors such as optical and electrochemical biosensors have been reported. [Pg.535]

By immobilizing Mn(III)-tetrakis(4-sulfonatophenyl)-porphyrin on dioctadecyl-dimethyl ammonium chloride bilayer membranes incorporated into a PVC film, Kuniyoshi et al. [65] developed an epinephrine CL sensor, which allowed determination of epinephrine down to 3 pM with an RSD of 1.0% for 50 pM of this biological compound. Compared with the previously reported epinephrine CL sensor [66], the present authors noted that the alkaline carrier solution, at high concentration levels, caused gradual deterioration of the immobilized catalyst, and this problem could be solved by the use of immobilization techniques other than ion exchange, e.g., solubilization of the catalyst that has octadecyl groups in the bilayer molecules. [Pg.582]

Structural characterizations of the immobilized bilayer assemblies are essential for the molecular design of the functional materials. On the bases of the systematic crystallographic investigation of single crystals of double-chain ammonium amphiphiles [9], Okuyama wrote a computer simulation program for the calculation of bilayer structures in cast bilayer films and bilayer thicknesses estimated from the repeating period in the X-ray diffraction data have been exclusively used for structural discussions [10,11]. [Pg.50]

Immobilization of bilayer membranes as ultra thin polymer films... [Pg.75]

Immobilization of the bilayer membranes as thin solid films is required when the bilayer membranes are used as novel functional materials. Casting method is a simple way to immobilize the bilayer membrane on a solid support from an aqueous solution by drying. Polymer film is easily prepared when the cast film of polymerizable bilayer membrane is polymerized. A free standing polymer film prepared by photo polymerization of the cast film of diacetylene amphiphiles was reported by O Brien and co-workers [34]. Composition with macromolecular materials is another way of polymer film preparation. Bilayer membranes are immobilized as polymer composites by the following physical methods ... [Pg.75]

Polyion complex technique [40] is a unique method for immobilization of bilayer membranes with polymers. Water-insoluble complex is precipitated as the polyion complex when an aqueous solution of the charged bilayer membrane is mixed with a water solution of the counter charged polyelectrolyte. Stoichiometric ion pair formation is often found. Aging of the precipitate in a hot mixture kept above phase transition temperature of the bilayer membrane completes the ion exchange reaction [41], Chloroform solution of the polyion complex is washed by water several times to remove water soluble components [42]. [Pg.76]

The fundamental bilayer characteristics (two-dimensional ordering, phase transition, and phase separation, etc.,) are mostly maintained in the immobilized films with and without polymers. Aging or thermal treatment on the as-cast films improve the film properties because... [Pg.76]

Photochemical switching of the phase transition is also found in the polyion complex film. Figure 29 shows reversible cycles of the absorption at 370nm by the coupling of the thermal and photoinduced phase transition of the complex film with carboxymethylcellulose 8. In conclusion, we indicate that the immobilized bilayer membranes containing the azobenzene chromophore are available to the erasable memory materials based on the phase transition triggered by thermal and photochemical processes. The polyion complex technique is clearly shown to be a very useful method for materialization of the immobilized bilayer membranes. [Pg.79]

Using a concentration jump as the perturbation, Sutherland et a/.(113) measured the kinetics of binding of fluorescein-labeled human IgG (present as an antigen in solution) to surface-immobilized sheep anti-human IgG. Two TIRF surfaces were used a planar slide and a fiber-optic cylinder. Also using a TIRF recovery after a concentration jump, Kalb et a/,(114) measured the slow ( 10 4 s 1) unbinding kinetics of anti-trinitrophenol (TNP) antibodies in solution and a TNP-derivatized lipid in a planar bilayer. [Pg.330]

The basic principle is shared by several methods In chromatographic or electrophoretic systems where the liposomes (vesicles) are immobilized, pseudostationary, or carried by an electroendosmotic flow, migrating amphiphilic drug molecules partition between the water outside the liposomes, the lipid bilayer of the liposome, and the aqueous compartment within the liposome (Fig. 3). In all cases the migration rate basically reflects the par-... [Pg.168]

The ACE analysis of interactions between drugs and phospholipid bilayers of liposomes present as a pseudostationary phase was performed by Zhang et al. (32). The capillaries were treated to eliminate electroendosmosis. Freshly prepared and essentially neutral small unilamellar liposomes composed of egg phosphatidylcholine were sucked into the capillary. These liposomes increased both the retention of four negatively charged drugs and the separation between the substances (Fig. 6). The chromatographic retentions of these drugs on immobilized phosphatidylcholine liposomes, ex-... [Pg.175]

C Lagerquist, F Beigi, A Karlen, H Lennernas, P Lundahl. Effects of cholesterol and model transmembrane proteins on drug partitioning into lipid bilayers as analyzed by immobilized-liposome chromatography. J Pharm Pharmacol 53 1477-1487, 2001. [Pg.181]


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See also in sourсe #XX -- [ Pg.64 ]




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Immobilized bilayers

Immobilized bilayers

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