NMR studies of calcium‐induced alginate gelation. Part I—MRI tests of gelation models

Duez, J.‐M.; Mestdagh, Michèle; Demeure, Roger; Goudemant, Jean-François; Hills, B.P.; Godward, John

doi:10.1002/1097-458x(200005)38:5<324::aid-mrc646>3.3.co;2-t

Cited by 9 publications

(29 citation statements)

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“…Two commonly used techniques for evaluating particle size and morphology are laser diffraction analysis and microscopy (Gavini et al, 2005;Klokk and Melvik, 2002;Kortesuo et al, 2000;Rosinski et al, 2002). Nuclear Magnetic Resonance (NMR) can also be used for examining porosity of gel particles as well as observing the gelation process (Dobies et al, 2005;Duez et al, 2000;Hills et al, 2000).…”

Section: Particle Size Shape and Structurementioning

confidence: 99%

“…NMR techniques have more recently been used to study internal gel particle structure as well as gelation of gel particles (Dobies et al, 2005;Duez et al, 2000;Grant et al, 2005;Hills et al, 2000). In these studies, water proton relaxation time distributions are obtained, to complement the information on the hydrocolloid architecture observable from SEM or TEM.…”

Section: Downloaded By [University Of Massachusetts Amherst] At 05:3mentioning

confidence: 99%

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Hydrocolloid Gel Particles: Formation, Characterization, and Application

Burey

Bhandari

Howes

et al. 2008

Critical Reviews in Food Science and Nutrition

346

186

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Hydrocolloid gel particles of micron and sub-micron size are particularly attractive for use in many applications in the food, agricultural, pharmaceutical, and chemical industries, due to their biocompatibility, perception as "natural" materials, and soft-solid texture. Industrial applications for such particles include uses as texturizers in confectionery and cosmetic products, slow-release encapsulation agents for flavors, nutrients, and pharmaceutical products, and thickeners in soups and sauces. Properties such as particle size, hardness, shape, texture, and molecular release rates can be important for individual applications. In addition, product formats will determine specific needs for physical form (e.g. dry or wet) and compatibility with other components. The diverse range of potential applications for hydrocolloid gel particles provide a driver for understanding-led tailoring of raw material and process conditions. This review introduces some of the materials that are used to form hydrocolloid gel particles and the corresponding gel formation mechanisms. One issue of importance in the production of hydrocolloid gel particles is the control of particle properties, such as release profiles, strength, and detectability within products. An alternative technique to traditional methods of hydrocolloid gel particle production is evaluated and a model for control of particle size, and subsequently other particle properties, is proposed. Key properties of hydrocolloid gel particles are identified and characterization methods for evaluating these properties are described.

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Section: Particle Size Shape and Structurementioning

confidence: 99%

Section: Downloaded By [University Of Massachusetts Amherst] At 05:3mentioning

confidence: 99%

Hydrocolloid Gel Particles: Formation, Characterization, and Application

Burey

Bhandari

Howes

et al. 2008

Critical Reviews in Food Science and Nutrition

346

186

View full text Add to dashboard Cite

show abstract

“…Toward this end, magnetic resonance (MR) microscopy has been applied to measure the spatially resolved water, spin–lattice relaxation ( T 1 ), spin–spin relaxation ( T 2 ) and molecular diffusion during the time‐dependent heterogeneous reaction diffusion front formation of alginate gel. Significant MR studies on this type of gel have been conducted,13–20 but have not focused on capillary structure formation. Theoretical modeling of the interaction of cation transport and gelation21, 22 in the absence of capillary formation have been undertaken.…”

Section: Introductionmentioning

confidence: 99%

“…In contrast to the moving front model, the continuum transport model does not define a discrete front where reaction occurs but rather allows for a balance of diffusion and reaction amongst the reactants to produce regions of strongly different composition (gel and alginate solution). Given a particular geometry along with an appropriate boundary and initial conditions, the solutions to this set of equations can be computed numerically 17, 21, 26. Reaction diffusion systems in which the reactants are initially separated provide a more controlled experimental system27 and are necessary for capillary formation 9.…”

Section: Introductionmentioning

confidence: 99%

Binding of Topotecan to a Nicked DNA Oligomer in Solution

Bocian

Kawęcki

Bednarek

et al. 2008

Chemistry A European J

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Topotecan (TPT) is in clinical use as an antitumor agent. It acts by binding to the covalent complex formed between nicked DNA and topoisomerase I, and inserts itself into the single-strand nick, thereby inhibiting the religation of the nick and acting as a poison. A crystal structure analysis of the ternary complex has shown how the drug binds (B. L. Staker, K. Hjerrild, M. D. Feese, C. A. Behnke, A. B. Burgin, L. Stewart, Proc. Natl. Acad. Sci. U.S.A., 2002, 99, 15 387-15 392), but has left a number of unanswered questions. Herein, we use NMR spectroscopy and molecular modeling to show that the solution structure of a complex of TPT with nicked natural DNA is similar, but not identical to the crystal conformation, and that other geometries are of very low population. We also show that the lactone form of TPT binds approximately 40 times more strongly than the ring-opened carboxylate.

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“…The metal‐treated alginate hydrogels have been used as scaffolds in tissue engineering,8 as biomaterial,9 in cell culture/transplantation,10 and in cell immobilization 11. The internal bead structure,12 gelation models,13 and viscoelastic properties14 of the calcium alginates have been studied in detail. On the other hand, chemically–crosslinked alginate hydrogels have been used as a controlled release medium for drugs,15–19, pesticides,20 superabsorbent filament fibers,21 and flocculants 22.…”

Section: Introductionmentioning

confidence: 99%

Elastic, Superporous Hydrogel Hybrids of Polyacrylamide and Sodium Alginate

Omidian¹,

Rocca²,

Park

2006

Macromolecular Bioscience

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A novel approach was developed to prepare a superporous hydrogel with superior mechanical and elastic properties. According to this method, a synthetic monomer was polymerized and crosslinked in the presence of a water-soluble alginate polymer. Later in the process, the alginate part of the synthesized hydrogel was treated with metal cations, which resulted in a hydrogel hybrid with an interpenetrating network structure. In this article, a hydrogel hybrid of acrylamide and alginate is highlighted because of its unique swelling and mechanical properties. This hydrogel hybrid shows resilience and a rubbery property in its fully water-swollen state, which not previously been reported. To help understand the underlying mechanism responsible for such unique properties with hydrogel hybrids, the ionotropic gelation of the alginate polymer was also studied in more detail.

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NMR studies of calcium‐induced alginate gelation. Part I—MRI tests of gelation models

Cited by 9 publications

References 0 publications

Hydrocolloid Gel Particles: Formation, Characterization, and Application

Hydrocolloid Gel Particles: Formation, Characterization, and Application

Binding of Topotecan to a Nicked DNA Oligomer in Solution

Elastic, Superporous Hydrogel Hybrids of Polyacrylamide and Sodium Alginate

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