Studies on simple and mixed bile salt micelles by nuclear magnetic resonance spectroscopy

Small, Donald; Penkett, S. A.; Chapman, D.

doi:10.1016/0005-2760(69)90086-1

Cited by 371 publications

(262 citation statements)

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“…To obtain an aqueous dispersion, 1.2 wt.% of micronized graphite flakes are sonicated for ~3 h in a bath sonicator with 0.5 wt.% sodium deoxycholate (SDC), a bile salt surfactant. These surfactants, because of their flat molecular structure, adsorb readily on hydrophobic graphite surfaces [50,51]. Their β side has a larger contact area (1.8-3 nm 2 ) per surfactant molecule [52] than linear chain surfactants (e.g., sodium dodecylbenzene sulfonate (SDBS) [53,54]), which adsorb on graphitic surfaces through their alkyl chains [55].…”

Section: Device Fabrication and Characterizationmentioning

confidence: 99%

A stable, wideband tunable, near transform-limited, graphene-mode-locked, ultrafast laser

et al. 2010

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Section: Device Fabrication and Characterizationmentioning

confidence: 99%

A stable, wideband tunable, near transform-limited, graphene-mode-locked, ultrafast laser

et al. 2010

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“…Three models have been proposed: primary micelles, which are formed at low detergent concentration, having a disk shaped structure with one or two bile salt layers (model I) [31][32][33], and at higher detergent concentration, secondary micelles, where the aggregates are stabilised via hydrogen bondings between different primary micelles. Kawamura et al [34] have proposed another model, where the aggregates form a disk shaped structure with a single bile salt layer (model II).…”

Section: Compartment Concentrationmentioning

confidence: 99%

Membranolytic Activity of Bile Salts: Influence of Biological Membrane Properties and Composition

et al. 2007

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Abstract:The two main steps of the membranolytic activity of detergents: 1) the partitioning of detergent molecules in the membrane and 2) the solubilisation of the membrane are systematically investigated. The interactions of two bile salt molecules, sodium cholate (NaC) and sodium deoxycholate (NaDC) with biological phospholipid model membranes are considered. The membranolytic activity is analysed as a function of the hydrophobicity of the bile salt, ionic strength, temperature, membrane phase properties, membrane surface charge and composition of the acyl chains of the lipids. The results are derived from calorimetric measurements (ITC, isothermal titration calorimetry). A thermodynamic model is described, taking into consideration electrostatic interactions, which is used for the calculation of the partition coefficient as well as to derive the complete thermodynamic parameters describing the interaction of detergents with biological membranes (change in enthalpy, change in free energy, change in entropy etc). The solubilisation properties are described in a so-called vesicle-to-micelle phase transition diagram. The obtained results are supplemented and confirmed by data obtained from other biophysical techniques (DSC differential scanning calorimetry, DLS dynamic light scattering, SANS small angle neutron scattering).

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“…Although they are comparable to common surfactants, the general conclusion is that biosurfactants self-assemble in a different way than the standard surfactants. [1][2][3][4][5][6][7][8][9][10][11][12][13] Poly(ethyleneimine) (PEI) is a member of a large family of water-soluble polyamines having different molecular weights (M w ) and polymer architectures. Polyamines are weak bases and exhibit a cationic character depending on the degree of protonation.…”

Section: Introductionmentioning

confidence: 99%

Supramolecular complexes formed by the association of poly(ethyleneimine) (PEI), sodium cholate (NaC) and sodium dodecyl sulfate (SDS)

Felippe

Bellettini

Eising

et al. 2011

J. Braz. Chem. Soc.

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A formação de complexos supramoleculares em solução aquosa pela associação do polieletrólito poli(etilenoimina) (PEI) com misturas do biossurfactante colato de sódio (NaC) e o surfactante aniônico dodecil sulfato de sódio (SDS) foi aqui investigado usando as técnicas de condutivimetria, tensiometria, fluorimetria, espalhamento de raios X a baixos ângulos (SAXS) e medidas de pH. Os resultados de fluorimetria, condutivimetria e medidas de pH levaram à conclusão de que os monômeros de NaC e SDS ligam-se primeiramente em sítios específicos das cadeias do polieletrólito PEI via interação eletrostática e posteriormente através de associação cooperativa. A interação do NaC com o PEI é mais fraca do que a interação do SDS com o PEI, porém, a adição de SDS ao sistema NaC-PEI levou à formação de micelas mistas SDS-NaC que interagiram fortemente com o polieletrólito PEI. Os resultados de SAXS sugeriram que o complexo supramolecular possui característica elipsoidal e essa forma não depende da concentração de surfactante nem da χ NaC .The formation of supramolecular complexes produced by association of poly(ethyleneimine) (PEI) and mixtures of sodium cholate (NaC) and sodium dodecyl sulfate (SDS) was investigated by pH, electrical conductivity, fluorescence spectroscopy and small angle X-ray scattering (SAXS) measurements. The fluorescence linked to previously measured values of pH and conductivity led to the conclusion that NaC and SDS molecules firstly bind to specific sites of the PEI chains via electrostatic interaction and secondly undergo self-assembly through regular cooperative association. The interaction of NaC with the polyelectrolyte PEI is weaker than that of SDS and the addition of SDS to the NaC-PEI system led to the formation of mixed NaC-SDS micelles which stronger interact with PEI. The SAXS results suggested that the micellar aggregates have a considerably ellipsoidal characteristic and the micellar shape is not affected by the surfactant concentration nor by χ NaC .Keywords: sodium cholate, sodium dodecyl sulfate, poly(ethyleneimine), polymer-surfactants interaction IntroductionBile salts are naturally-occurring amphiphilic molecules. They are physiologically important in the solubilization and transport of fats and lipids. The structure of bile salts in water has been extensively investigated. Although they are comparable to common surfactants, the general conclusion is that biosurfactants self-assemble in a different way than the standard surfactants. [1][2][3][4][5][6][7][8][9][10][11][12][13] Poly(ethyleneimine) (PEI) is a member of a large family of water-soluble polyamines having different molecular weights (M w ) and polymer architectures. Polyamines are weak bases and exhibit a cationic character depending on the degree of protonation. PEI has been extensively studied (particularly the branched form) due to its intense use in the formulation of drugs, thickeners, flocculating agents, personal care products, food products, detergents and adhesives. It has also been used for biological proposes to p...

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Studies on simple and mixed bile salt micelles by nuclear magnetic resonance spectroscopy

Cited by 371 publications

References 15 publications

A stable, wideband tunable, near transform-limited, graphene-mode-locked, ultrafast laser

A stable, wideband tunable, near transform-limited, graphene-mode-locked, ultrafast laser

Membranolytic Activity of Bile Salts: Influence of Biological Membrane Properties and Composition

Supramolecular complexes formed by the association of poly(ethyleneimine) (PEI), sodium cholate (NaC) and sodium dodecyl sulfate (SDS)

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