1H NMR studies on intermolecular association of amphiphilic cationic polyelectrolyte micelles induced by hydrophobic counteranions in water

Wu, Huawei; Kawaguchi, Seigou; Ito, Koichi

doi:10.1007/s00396-004-1194-0

Cited by 14 publications

(12 citation statements)

References 26 publications

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“…Conversely, IMC that is not spatially restricted would have the same hydrodynamic radius as the free molecule. [21,22,[26][27][28][35][36][37] ] The results of these experiments indicate that IMC is loaded by the ASM, despite the presence of an organic solvent. As such, it is likely that the IMC has favorable interactions with the hydrophobic domain of the ASM.…”

Section: Dosymentioning

confidence: 86%

“…[16,17] The hydrophobic proton intensities that are reduced (H 9-11 ) indicate that part of the core is less constrained, consistent with an interfacial region. [16,17,21] The integrations of hydrophilic ASM components, such as the PEG methylenes (H 2-4 ) and terminal methoxy protons (H 1 ), remain unaffected by D 2 O, indicating that they are fully hydrated. These findings support a gradientlike structure in which the ASM exists as a single phase, capable of interacting with IMC in both the hydrophobic core and the interfacial region.…”

Section: H Nmr Spectroscopymentioning

confidence: 99%

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Spatial location of indomethacin associated with unimeric amphiphilic carrier macromolecules as determined by nuclear magnetic resonance spectroscopy

Orban

Moretti

Uhrich

2016

Magnetic Reson in Chemistry

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A combination of nuclear magnetic resonance (NMR) techniques including, proton NMR, relaxation analysis, two-dimensional nuclear Overhauser effect spectroscopy, and diffusion-ordered spectroscopy, has been used to demonstrate the spatial location of indomethacin within a unimolecular micelle. Understanding the location of drugs within carrier molecules using such NMR techniques can facilitate rational carrier design. In addition, this information provides insight to encapsulation efficiency of different drugs to determine the most efficient system for a particular bioactive. This study demonstrates that drugs loaded by the unimolecular amphiphile under investigation are not necessarily encapsulated but reside or localize to the periphery or interfacial region of the carrier molecule. The results have further implications as to the features of the unimolecular carrier that contribute to drug loading. In addition, evidence of drug retention associated with the unimolecular surfactant is possible in organic media, as well as in an aqueous environment. Such findings have implications for rational carrier design to correlate the carrier features to the drug of interest and indicate the strong retention capabilities of the unimolecular micelle for delivery applications. Copyright © 2016 John Wiley & Sons, Ltd.

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Section: Dosymentioning

confidence: 86%

Section: H Nmr Spectroscopymentioning

confidence: 99%

Spatial location of indomethacin associated with unimeric amphiphilic carrier macromolecules as determined by nuclear magnetic resonance spectroscopy

Orban

Moretti

Uhrich

2016

Magnetic Reson in Chemistry

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“…The salts in the pH 3 and 10 buffers were potassium hydrogen phthalate and borax, respectively. 10 In this system the salt concentration was maintained and the only difference was the polymer concentration, achieved by adding PAH. The dynamic behavior of the polymer with different concentrations was studied by DLS and zeta-potentiometer.…”

Section: Resultsmentioning

confidence: 99%

Aggregation Processes of a Weak Polyelectrolyte, Poly(allylamine) Hydrochloride

Park

Choi

Kim

et al. 2008

Bulletin of the Korean Chemical Society

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Poly(allylamine) hydrochloride is a weak cationic polyelectrolyte that exhibits different aggregation properties at different solution pH values and aging times. Specifically, after several days aging in a pH 3 buffer, less than 1 mg/mL poly(allylamine) hydrochloride became turbid, and the hydrodynamic radius increased with a single diffusion mode. However, the hydrodynamic radius did not change at high concentrations. The dynamic processes of polymer aggregations at different pH values were verified by a light scattering and zeta-potential apparatus. The major interaction was caused by the capturing of counterions by the polyelectrolyte, which generates electrostatic, hydrophobic and cation-π interactions.

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“…Their polymerized micelles maintained their threadlike shape but became shorter as the polymerization reaction progressed, as in Kline's system, and consequently their solution lost its high viscoelasticity after polymerization. Kawaguchi et al [27,28] prepared viscoelastic aqueous micellar solutions consisting of polymerized cationic surfactant monomers and additive salts. Although they did not investigate the structure of the micelles, their systems showed marked viscoelasticity and the components used were similar to those in Kaler's system to strongly suggest that their micelles also had a long threadlike shape.…”

Section: Introductionmentioning

confidence: 99%

Formation and Physicochemical Features of Hybrid Threadlike Micelles in Aqueous Solution

Nakamura

Shikata

2007

ChemPhysChem

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We investigate the construction of long, stable hybrid threadlike micelles consisting of polyelectrolytes and oppositely charged surfactants in aqueous solution and examine the physicochemical features such as their structure and viscoelastic behavior in aqueous solution. The most important point for their construction is the careful control of interactions, especially electrostatic interactions, caused between the surfactants and polyelectrolytes. Incorporated polyelectrolytes are fully extended in these hybrid threadlike micelles irrespective of the molecular weight of the polymer. The viscoelastic behavior of the hybrid threadlike micellar solution is similar to that of ordinary threadlike micellar systems consisting of low-molecular-weight substances. However, the inclusion of polymers in the micelles causes differences in their mechanical properties.

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1H NMR studies on intermolecular association of amphiphilic cationic polyelectrolyte micelles induced by hydrophobic counteranions in water

Cited by 14 publications

References 26 publications

Spatial location of indomethacin associated with unimeric amphiphilic carrier macromolecules as determined by nuclear magnetic resonance spectroscopy

Spatial location of indomethacin associated with unimeric amphiphilic carrier macromolecules as determined by nuclear magnetic resonance spectroscopy

Aggregation Processes of a Weak Polyelectrolyte, Poly(allylamine) Hydrochloride

Formation and Physicochemical Features of Hybrid Threadlike Micelles in Aqueous Solution

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