Browsing NTNU Open by Author "Skjåk-Bræk, Gudmund"
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Alginat - protein interaksjoner
Kristoffersen, Lill June (Master thesis, 2011)Lite er kjent i forhold til proteiners interaksjon med alginat, noe som er viktig å ha kjennskap til ved bruk av biopolymeren som immobiliseringsmateriale for celler og proteiner. Denne oppgaven er derfor en studie av ... -
Alginate microbeads are complement compatible, in contrast to polycation containing microcapsules, as revealed in a human whole blood model
Rokstad, Anne Mari; Brekke, Ole Lars; Steinkjer, Bjørg; Ryan, Liv; Kolláriková, Gabriela; Strand, Berit Løkensgard; Skjåk-Bræk, Gudmund; Lacík, Igor; Espevik, Terje; Mollnes, Tom Eirik (Journal article; Peer reviewed, 2011)Alginate microbeads and microcapsules are presently under evaluation for future cell-based therapy. Defining their inflammatory properties with regard to humans is therefore essential. A lepirudine-based human whole blood ... -
Alginate Microcapsules for Cell Therapy: Effect of capsule composition on complement activation, cytokine secretion, and protein adsorption in a whole blood model
Ørning, Mathias Pontus Andreas (Master thesis, 2012)Encapsulation of pancreatic islets in alginate microbeads and microcapsules show great promise for the treatment of Type 1 diabetes mellitus. Significant progress has been made in developing a biocompatible capsule that ... -
Alginate microsphere compositions dictate different mechanisms of complement activation with consequences for cytokine release and leukocyte activation
Ørning, Mathias Pontus; Hoem, Kine Samseth; Coron, Abba Elizabeth; Skjåk-Bræk, Gudmund; Mollnes, Tom Eirik; Brekke, Ole Lars; Espevik, Terje; Rokstad, Anne Mari (Journal article; Peer reviewed, 2016)The inflammatory potential of 12 types of alginate-based microspheres was assessed in a human whole blood model. The inflammatory potential could be categorized from low to high based on the four main alginate microsphere ... -
Alginate modification with the coupling of primary amines relevant for nerve regeneration
Abdoli Najmi, Maryam (Master thesis, 2014)Alginate is a polysaccharide produced by brown seaweed and some bacteria which is highly demanded in biomedical researches. It can form a gel in presence of divalent cations which has many applications in cell based therapy. ... -
Analysis of G-Block Distributions and Their Impact on Gel Properties of in Vitro Epimerized Mannuronan
Aarstad, Olav Andreas; Strand, Berit Løkensgard; Klepp-Andersen, Lise Mari; Skjåk-Bræk, Gudmund (Journal article; Peer reviewed, 2013)This paper reports a study of the distribution and function of homopolymeric guluronic acid blocks (G-blocks) in enzymatically modified alginate. High molecular weight mannuronan was incubated with one native (AlgE6) and ... -
Ancient acquisition of "alginate utilization loci" by human gut microbiota
Mathieu, Sophie; Touvrey-Loiodice, Melanie; Poulet, Laurent; Drouillard, Sophie; Vincentelli, Renaud; Henrissat, Bernard; Skjåk-Bræk, Gudmund; Helbert, William (Journal article; Peer reviewed, 2018)In bacteria from the phylum Bacteroidetes, the genes coding for enzymes involved in polysaccharide degradation are often colocalized and coregulated in so-called “polysaccharide utilization loci” (PULs). PULs dedicated to ... -
Biomimetic sulphated alginate hydrogels suppress IL-1B-induced inflammatory responses in human chondrocytes
Arlov, Øystein; Öztürk, E.; Steinwachs, M.; Skjåk-Bræk, Gudmund; Zenobi-Wong, M. (Journal article; Peer reviewed, 2017)Loss of articular cartilage from ageing, injury or degenerative disease is commonly associated with inflammation, causing pain and accelerating degradation of the cartilage matrix. Sulphated glycosaminoglycans (GAGs) are ... -
Biosynthesis and Function of Long Guluronic Acid-Blocks in Alginate Produced by Azotobacter vinelandii
Aarstad, Olav Andreas; Stanisci, Annalucia; Sætrom, Gerd Inger; Tøndervik, Anne; Sletta, Håvard; Aachmann, Finn Lillelund; Skjåk-Bræk, Gudmund (Journal article; Peer reviewed, 2019)With the present accessibility of algal raw material, microbial alginates as a source for strong gelling material are evaluated as an alternative for advanced applications. Recently, we have shown that alginate from algal ... -
Characterization of Sulfated Alginate Hybrid Gels for Tissue Engineering
Aaen, Ragnhild (Master thesis, 2015)Tissue engineering is a field aiming to replace damaged tissue while reducing the great need of organ donors the world is facing today. Alginates are linear co-polymers consisting of the two monosaccharides β-D-mannuronic ... -
Current and Future Perspectives on Alginate Encapsulated Pancreatic Islet
Strand, Berit Løkensgard; Coron, Abba Elizabeth; Skjåk-Bræk, Gudmund (Journal article; Peer reviewed, 2017)Transplantation of pancreatic islets in immune protective capsules holds the promise as a functional cure for type 1 diabetes, also about 40 years after the first proof of principal study. The concept is simple in using ... -
Encapsulation of Human Mesenchymal Stem Cells in Phosphate Mineralized Alginate Beads
Westhrin, Marita (Master thesis, 2011)Alginate scaffolds show good promise for bone tissue engineering using stem cells. This is due to the fact that alginate is biocompatible, non-immunogenic, and in addition may direct differentiation of stem cells into a ... -
Energy Landscape of Alginate-Epimerase Interactions Assessed by Optical Tweezers and Atomic Force Microscopy
Håti, Armend Gazmeno; Aachmann, Finn Lillelund; Stokke, Bjørn Torger; Skjåk-Bræk, Gudmund; Sletmoen, Marit (Journal article, 2015)Mannuronan C-5 epimerases are a family of enzymes that catalyze epimerization of alginates at the polymer level. This group of enzymes thus enables the tailor-making of various alginate residue sequences to attain various ... -
Evidence for egg-box-compatible interactions in calcium-alginate gels from fiber X-ray diffraction
Sikorski, Pawel; Mo, Frode; Skjåk-Bræk, Gudmund; Stokke, Bjørn Torger (Peer reviewed; Journal article, 2007)The structures of guluronic-acid-rich alginate in the acid and calcium forms were investigated using fiber X-ray diffraction. Data recorded for alginate fibers in the acid form show a repeat along the chain axis of c = ... -
Exploiting mannuronan C-5 epimerases in commercial alginate production
Tøndervik, Anne; Aarstad, Olav Andreas; Aune, Randi; Maleki, Susan; Rye, Philip D; Dessen, Arne; Skjåk-Bræk, Gudmund; Sletta, Håvard (Peer reviewed; Journal article, 2020)Alginates are one of the major polysaccharide constituents of marine brown algae in commercial manufacturing. However, the content and composition of alginates differ according to the distinct parts of these macroalgae and ... -
Functional Exploration of the Polysaccharide Lyase Family PL6
Mathieu, Sophie; Henrissat, Bernard; Labre, Flavien; Skjåk-Bræk, Gudmund; Helbert, William (Journal article; Peer reviewed, 2016)Alginate, the main cell-wall polysaccharide of brown algae, is composed of two residues: mannuronic acid (M-residues) and, its C5-epimer, guluronic acid (G-residues). Alginate lyases define a class of enzymes that cleave ... -
GDF-15 signalling in multiple myeloma
Skjærvik, Anette (Master thesis, 2015)Abstract Multiple myeloma (MM), also known as bone marrow cancer, is a malignancy of hypermutated antibody-producing plasma cells in the bone marrow. An accumulation of this antibody (M-protein) can be detected in blood- ... -
Heparin Analogs Created by Sulfation of Alginates Using a Chemoenzymatic Strategy
Arlov, Øystein (Master thesis, 2012)Alginates are a class of natural unbranched linear polysaccharides, and consist of the monomers β-D-mannuronic acid and α-L-guluronic acid. The inherent physical properties, relative ease of modification, wide availability ... -
Identification of a Pivotal Residue for Determining the Block Structure-Forming Properties of Alginate C-5 Epimerases
Stanisci, Annalucia; Tøndervik, Anne; Gaardløs, Margrethe; Lervik, Anders; Skjåk-Bræk, Gudmund; Sletta, Håvard; Aachmann, Finn Lillelund (Peer reviewed; Journal article, 2020)Alginate is a linear copolymer composed of 1→4 linked β-d-mannuronic acid (M) and its epimer α-l-guluronic acid (G). The polysaccharide is first produced as homopolymeric mannuronan and subsequently, at the polymer level, ... -
Mannuronan C-5 Epimerases Suited for Tailoring of Specific Alginate Structures Obtained by High-Throughput Screening of an Epimerase Mutant Library
Tøndervik, Anne; Klinkenberg, Geir; Aachmann, Finn Lillelund; Svanem, Britt Iren Glærum; Ertesvåg, Helga; Ellingsen, Trond Erling; Valla, Svein; Skjåk-Bræk, Gudmund; Sletta, Håvard (Journal article; Peer reviewed, 2013)The polysaccharide alginate is produced by brown algae and some bacteria and is composed of the two monomers, β-d-mannuronic acid (M) and α-l-guluronic acid (G). The distribution and composition of M/G are important for ...