Glucosamine Research Today is a free monthly online journal that collates and summarizes the latest research about Glucosamine, including details on chondroitin sulfate, uses, effects, benefits, arthritis.

Synthesis of GTMAC modified chitin-PAA gel and evaluation of its biological properties.

Uppanan P, Channasanon S, Veeranondh S, Tanodekaew S

National Metal and Materials Technology Center, 114 Thailand Science Park, Paholyothin Rd., Klong 1, Klong Luang, Pathumthani 12120, Thailand.

The dressing prepared from GTMAC modified chitin-PAA was introduced with the aim of facilitating wound healing, particularly those effectively absorbing exudates, maintaining a moist wound environment and controlling bacterial proliferation. Chitin was chemically modified with acrylic acid to encourage a moist wound healing environment. The highly water-absorbable resulting product (chitin-PAA) was further reacted with glycidyltrimethylammonium chloride (GTMAC) to impart antibacterial activities. The final product, chitin-PAA-GTMAC was characterized by the techniques of Fourier Transform Infrared (FTIR), solid state (15) N NMR, and elemental analysis. Their cytotoxicity and antibacterial activities against S. epidermidis and E. coli were evaluated which found increasing effects in those properties with increasing degree substitution of GTMAC. All materials also showed good blood-clotting ability. The collagen gel contraction assay was used to analyze the behavior of fibroblasts after contact with the gels. The extent of the gel contraction as well as the examination of the secreted interleukin-8 (IL-8) and transforming growth factor-β1 (TGF-β1) were investigated. The results showed that chitin-PAA modified with GTMAC could stimulate the production of IL-8, but TGF-β1. Fibroblasts presented normal spreading and formation of cellular processes in the collagen gels with all of the modifications. Furthermore, all modified gels except for the highest GTMAC content gel [chitin-PAA-GTMAC (1:20)] were found a greater extent in gel contraction than the unmodified chitin-PAA. It suggested the promoting effect of GTMAC on cell proliferation if the GTMAC content in the gel was not too high, that is, the mole ratio of glucosamine to GTMAC of the gel should not greater than 1:10. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: , 2011.

Published 6 May 2011 in J Biomed Mater Res A.
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Articles on Glucosamine published 5 May 2011:

Rapid Transformation of d-Mannose into Orthogonally Protected d-Glucosamine and d-Galactosamine Thioglycosides.   J Org Chem.

An expedient protocol for synthesis of orthogonally protected 2-azido-2-deoxy-d-glucosamine and 2-azido-2-deoxy-d-galactosamine donors from d-mannose is described. Readily available phenyl β-d-thiomannoside is rapidly transformed into d-GlcN(3) thioglycosides via a highly regioselective 3-O-acylation followed by 4,6-O-benzylidenation and azide displacement of C2-OTf, which is further converted into d-GalN(3) thioglycosides through Lattrell-Dax inversion of the C4 hydroxy group and its Boc ... [Abstract] [Full-text]

A fluorescence-based assay for measuring N-acetyl-1-d-myo-inosityl-2-amino-2-deoxy-α-d-glucopyranoside deacetylase activity.   Anal Biochem.

Here we report a new fluorescence-based assay for measuring MshB (N-acetyl-1-d-myo-inosityl-2-amino-2-deoxy-α-d-glucopyranoside deacetylase) activity. The current assay for measuring MshB activity requires the fluorescent labeling of reaction mixtures and subsequent analysis using high-performance liquid chromatography (HPLC), resulting in a significant amount of processing time per sample. Here we describe a more rapid fluorescnce-based assay for the measurement of MshB activity that does not ... [Abstract] [Full-text]

Articles on Glucosamine published 4 May 2011:

Chemical reporters for fluorescent detection and identification of O-GlcNAc-modified proteins reveal glycosylation of the ubiquitin ligase NEDD4-1.   Proc Natl Acad Sci U S A.

The dynamic modification of nuclear and cytoplasmic proteins by the monosaccharide N-acetyl-glucosamine (GlcNAc) continues to emerge as an important regulator of many biological processes. Herein we describe the development of an alkynyl-modified GlcNAc analog (GlcNAlk) as a new chemical reporter of O-GlcNAc modification in living cells. This strategy is based on metabolic incorporation of reactive functionality into the GlcNAc biosynthetic pathway. When combined with the Cu(I)-catalyzed ... [Abstract] [Full-text]

Keratinocytes stimulate fibroblast hyaluronan synthesis through the release of stratifin: A possible role in the suppression of scar tissue formation.   Wound Repair Regen, 19(3): 379-86.

Scar tissue formation during healing of extensive skin wounds may be related to delayed reepithelialization, while elevated levels of hyaluronan may suppress scar tissue formation. This study investigates the expression of hyaluronan by human skin fibroblasts in response to keratinocyte-conditioned medium (KCM), and attempts to identify any active factors within the conditioned medium. Serum-free KCM was assessed for its ability to stimulate the incorporation of (3) H-glucosamine into ... [Abstract] [Full-text]

M-Ficolin Interacts with the Long Pentraxin PTX3: A Novel Case of Cross-Talk between Soluble Pattern-Recognition Molecules.   J Immunol, 186(10): 5815-22.

Ficolins and pentraxins are soluble oligomeric pattern-recognition molecules that sense danger signals from pathogens and altered self-cells and might act synergistically in innate immune defense and maintenance of immune tolerance. The interaction of M-ficolin with the long pentraxin pentraxin 3 (PTX3) has been characterized using surface plasmon resonance spectroscopy and electron microscopy. M-ficolin was shown to bind PTX3 with high affinity in the presence of calcium ions. The interaction ... [Abstract] [Full-text]

Articles on Glucosamine published 3 May 2011:

Effect of glucosamine, a therapeutic agent for osteoarthritis, on osteoblastic cell differentiation.   Int J Mol Med.

Osteoarthritis (OA) is characterized by qualitative and quantitative changes in the architecture and composition of all the joint structures. Glucosamine (GlcN) has been used to treat OA in humans, because GlcN is present in the cartilage tissues as a component of glycosaminoglycans, and exhibits the symptom-modifying effect on OA by normalizing cartilage metabolism. On the other hand, the pathological change of subchondral bone is associated with the initiation and progression of cartilage ... [Abstract] [Full-text]

Enzymatic Placement of 6-O-Sulfo Groups in Heparan Sulfate.   Biochemistry.

Heparan sulfate is a highly sulfated polysaccharide that exhibits important physiological and pathological functions. The glucosamine residue of heparan sulfate can carry sulfo groups at the 2-N, 3-O, and 6-O positions, leading to diverse polysaccharide structures. 6-O-Sulfation at the glucosamine residue contributes to a wide range of biological functions. Here, we report a method for controlling the positioning of 6-O-sulfo groups in oligosaccharides. This was achieved by synthesizing ... [Abstract] [Full-text]

Articles on Glucosamine published 2 May 2011:

Characterization, localization, essentiality and high-resolution crystal structure of Glucosamine 6-phosphate N-Acetyltransferase from Trypanosoma brucei.   Eukaryot Cell.

A gene predicted to encode Trypanosoma brucei glucosamine 6-phosphate N-acetyltransferase (EC 2.3.1.4, TbGNA1) was cloned and expressed in Escherichia coli. The recombinant protein was enzymatically active and its high-resolution crystal structure obtained at 1.86 Å. Endogenous TbGNA1 protein was localized to the peroxisome-like microbody, the glycosome. A bloodstream form T. brucei GNA1 conditional null mutant was constructed and shown to be unable to sustain growth in vitro under ... [Abstract] [Full-text]

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