Journal ArticleDOI
Small-Angle X-ray Scattering and Rheological Characterization of Alginate Gels. 1. Ca-Alginate Gels
Bjørn T. Stokke,Kurt Ingar Draget,Olav Smidsrød,Yoshiaki Yuguchi,Hiroshi Urakawa,Kanji Kajiwara +5 more
TLDR
In this article, small-angle X-ray scattering and rheology were used to determine relations between chemical composition and concentrations of the alginate and the elasticity and structure of the gels.Abstract:
Ca−alginate gels were studied by small-angle X-ray scattering and rheology to determine relations between chemical composition and concentrations of the alginate and the elasticity and structure of the gels. The gels were prepared by in situ release of Ca2+ from either Ca−EGTA or CaCO3 with total Ca2+ concentration in the range 5−30 mM. Alginates with low (39%), intermediate (50%), and high (68%) fractions of α-l-GulA originating from the brown algae Ascophyllum nodosum, Laminaria hyperborea leaf, and Laminaria hyperborea stipe, respectively, were employed. Two to three different degrees of polymerization for each chemical composition were used in the experiments. The excess small-angle X-ray scattering for the alginates in solution yielded linear cross-sectional Guinier plots, and the cross-sectional radius of gyration, Rg,c, was determined to be 3.1−4.6 A. The SAXS profiles of the alginate gels depended on the alginate concentration, Ca2+ concentration, and the alginate composition. The SAXS data sugges...read more
Citations
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Microencapsulation of probiotics for gastrointestinal delivery.
TL;DR: An overview of progress in this field is provided as well as drawing attention to areas where studies have fallen short, followed by a discussion of emerging trends in the field, highlighting key areas in which further research is necessary.
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Biofilm formation mechanisms and targets for developing antibiofilm agents
TL;DR: The current understanding of the processes that lead to biofilm formation in many bacteria is highlighted, and the identity of the key players are beginning to be uncovered.
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Chemical, physical and biological properties of alginates and their biomedical implications
TL;DR: It has quite recently also been shown that oligoguluronates are able to transiently modify mucin network structures to such an extent that it opens up possibilities for the treatment of pathological respiratory diseases as well as a general increased drug bioavailability due to increased mucosal uptake.
Journal ArticleDOI
Evidence for egg-box-compatible interactions in calcium-alginate gels from fiber X-ray diffraction.
TL;DR: The observations indicate that the junction zone involves dimerization of polymer chains through Ca2+ coordination according to the egg-box model, which involves polymer chains packed on a hexagonal lattice with a lattice constant a = 0.66 nm.
OtherDOI
Alginates from Algae
TL;DR: This chapter discusses alginates, alginic acid gels, and their applications in medicine and pharmacy, as well as some of the challenges faced by these companies in the rapidly changing environment.
References
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Journal ArticleDOI
Biological interactions between polysaccharides and divalent cations: The egg‐box model
TL;DR: It is shown that spedfic binding of divalent cations to a polysaechafide polyelectro]ym, leading firm cohesion between the chains, can cause characteristic effects in the c~rcutar diehroism spectrum which are understandabb in terms of modem theo~, [ l ].
Journal ArticleDOI
Insulin independence in a type 1 diabetic patient after encapsulated islet transplantation
P. Soon-Shiong,R. Heintz,N. Merideth,Q. X. Yao,Zhiwen Yao,Tianli Zheng,M. Murphy,M. K. Moloney,M. Schmehl,Michael Harris,R. Mendez,P. Sandford +11 more
TL;DR: Encapsulated human islets were injected intraperitoneally in a diabetic patient with a functioning kidney graft and insulin independence with tight glycaemic control was demonstrated 9 months after the procedure, warranting a trial of a high dose of encapsulated islets in early-onset diabetic patients.
Journal ArticleDOI
Towards a phenomenological definition of the term ‘gel’
TL;DR: It is proposed that the term ‘gel’ should be limited to systems which fulfil the following phenomenological characteristics: they consist of two or more components one of which is a liquid, present in substantial quantity and they are soft, solid, or solid-like materials.
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