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Microcapsules of alginate cross-linked with divalent ions are the most common system for cell immobilization. In this study, we wanted to characterize the effect of different alginates and cross-linking ions on important microcapsule properties. The dimensional stability and gel strength increased for high-G alginate gels when exchanging the traditional(More)
In this work we study (i) the formation and stabilization of silver nanoparticles in a bioactive chitosan-derived polysaccharide solution, (ii) the antimicrobial properties, either in solution or in 3D hydrogel structures, obtained by mixtures with the polysaccharide alginate, and (iii) the cytotoxicity of the latter nanocomposite materials on different(More)
The availability of mannuronan and mannuronan C-5 epimerases allows the production of a strictly alternating mannuronate-guluronate (MG) polymer and the MG-enrichment of natural alginates, providing a powerful tool for the analysis of the role of such sequences in the calcium-alginate gel network. In view of the calcium binding properties of long(More)
Alginate/hydroxyapatite composite scaffolds were developed using a novel production design. Hydroxyapatite (HAp) was incorporated into an alginate solution and internal gelling was induced by addition of slowly acid hydrolyzing d-gluconic acid delta-lactone (GDL) for the direct release of calcium ions from HAp. Hydrogels were then freeze-casted to produce a(More)
Bisphenol A glycidylmethacrylate (BisGMA)/triethyleneglycol dimethacrylate (TEGDMA) thermosets are biomaterials commonly employed for orthopedic and dental applications; for both these fields, bacterial adhesion to the surface of the implant represents a major issue for the outcome of the surgical procedures. In this study, the antimicrobial properties of a(More)
Alditol bearing chitosans have shown the ability to reduce silver ions in mild conditions and without addition of exogenous reducing agents. The ion reduction induces the formation of a lactone moiety on the polysaccharide (Fetizon reaction) without causing C-C bond cleavage on the polyol. The close and multivalent arrangement of the endogenous reducing(More)
Through enzymatic modification, we are now able to manipulate the composition and sequential nanostructures of alginate, one of the most versatile gelling polymers found in nature. Here we report the application of a set of processive polymer-modifying epimerases for the preparation of novel alginates with highly improved functional properties essential for(More)
Bisphenol A glycidylmethacrylate (BisGMA)/triethyleneglycol dimethacrylate (TEGDMA) thermosets are receiving increasing attention as biomaterials for dental and orthopedic applications; for both these fields, bacterial adhesion to the surface of the implant represents a major issue for the outcome of the surgical procedure. Moreover, the biological(More)
Coupling of alginate with 1-amino-1-deoxygalactose in the presence of 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide results in a substituted polymer containing galactose side linked via an amide bond. To clarify the degree and pattern of substitution, a (1)H NMR study on the anomeric region of modified alginate, polymannuronate, alginate enriched in(More)
There is an increased need for alginate materials with both enhanced and controllable mechanical properties in the fields of food, pharmaceutical and specialty applications. In the present work, well-characterized algal polymers and mannuronan were enzymatically modified using C-5 epimerases converting mannuronic acid residues to guluronic acid in the(More)