Ishurd O.,Biotechnology Research Center |
Zgheel F.,Biotechnology Research Center |
Elghazoun M.,Biotechnology Research Center |
Elmabruk M.,Biotechnology Research Center |
And 3 more authors.
Carbohydrate Polymers | Year: 2010
A water-soluble polysaccharide (PS-1) was isolated from the fruits of Opuntia ficus indica (L.) Miller by hot water extraction, anion-exchange and gel-permeation chromatography (yield 167.5 mg/kg raw fruit; [α] D161 + 192° (c 1.0, H2O); total neutral sugar content 96.60% w/w; weight-average molecular weight (M w) ∼360 kDa). Structural characterisation was performed by monosaccharide analysis and linkage analysis (methylation analysis, periodate oxidation and Smith degradation) on full and partial acid hydrolysates, followed by alditol acetylation, and product quantification by GC/GC-MS. Spectroscopic analysis (FT-IR and 1H/13C NMR) was also performed. Polysaccharide PS-1 was found to be an α-d-glucan with a (1 → 4)-linked α-d-Glcp backbone, with (1 → 6)-linked (1 → 4)-α-d-Glcp side chains, side chains being short in length with no additional branching, and a minimum branching of ∼1 in every 9-11 backbone units. The distribution of side chains lengths and corresponding branching density requires further investigation. © 2010 Elsevier Ltd. All rights reserved.
Tang Y.,Wuhan University |
Tang Y.,Nanyang Normal University |
Wang X.,South China University of Technology |
Li Y.,Wuhan University |
And 4 more authors.
Carbohydrate Polymers | Year: 2010
The properties of an injectable chitosan (CS)/methylcellulose (MC) blend hydrogel used as a three-dimensional synthetic matrix for tissue engineering were investigated. CS/MC hydrogels were prepared via blending of CS, MC and salts under mild conditions without organic solvent, high temperature or harsh pH. Such blends were liquid at low temperature (∼4 °C), but gel under physiological conditions (37 °C). The effect of different salts including NaCl, Na3PO4, NaHCO3 and glycerophosphate (GP) on the CS/MC gelation process was investigated by rheological analysis from which possible gelation mechanisms were inferred. Viscoelastic characteristics indicated that CS/MC gels formed using different salts had different gelation temperature, gelation rate, and gel strength. Gelation temperature followed the order NaCl > GP > Na3PO4 > NaHCO3, gelation rate followed the order GP > NaHCO3 > Na 3PO4, and gel strength followed the order GP > NaHCO3 > Na3PO4 (at 37 °C). CS/MC hydrogels were also characterised by infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). CS/MS gels formed with different salts had different gel structures, ranging from nonporous to microporous. When used as a scaffold for chondrocytes, CS/MC/Na 3PO4 hydrogel resulted in good cell viability and proliferation. © 2010 Elsevier Ltd. All rights reserved.
Anand S.C.,University of Bolton |
Kennedy J.F.,Advanced Science and Technology Ltd |
Miraftab M.,University of Bolton |
Rajendran S.,University of Bolton
Medical and Healthcare Textiles | Year: 2010
Medical textiles remain one of the most dynamic areas of research in textiles. Medical and healthcare textiles is the fourth in a series of conferences held at the University of Bolton. Like its predecessors, it has attracted papers from some of the leading international centres of expertise in the field. Contributors cover a range of topics including emerging textile-based biomaterials, hygienic textiles, the use of textiles in infection control and as barrier materials, bandaging and pressure garments for managing chronic infections such as ulcers, the role of textiles in the management of burns and wounds, textile-based implantable devices such as tissue scaffolds and sutures, and intelligent textiles. © 2010 Woodhead Publishing Limited. All rights reserved.
Wan Y.-Y.,Hubei University |
Wan Y.-Y.,Meiji University |
Lu R.,Meiji University |
Akiyama K.,Meiji University |
And 7 more authors.
International Journal of Biological Macromolecules | Year: 2010
The purified polysaccharides, glycoproteins, and isoenzymes of Rhus laccase, and crude enzymes, from Chinese lacquer (Rhus vernicifera sap) were used to determine their influence on the enzymic activity of Rhus laccase on several substrates (4-phenylenediamine, isoeugenol and coniferyl alcohol). No product identity changes were observed when these components were added singularly or in combination to the enzymic reactions (only relative product yields varied significantly), however, the polysaccharides (GP1 and GP2) and glycoprotein (stellacyanin, St) exhibited negative effects, and the two isoenzymes (L1 and L2) exhibited positive synergistic effects, on the activity of Rhus laccase. With respect to the activity of the crude enzymes, the negative effects of GP1, GP2 and St were greater than the positive effects of L1 and L2, compared with free Rhus laccase on its own (using 4-phenylenediamine as substrate), the estimated inhibitory effect (of GP1, GP2 and St) being by at least a factor of 50 (even with the positive effect of L1 and L2). This contributes to understanding of lacquer storage stability and drying rates. Immobilisation of crude enzymes using a variety of techniques (using natural and modified polysaccharides, and an inorganic support) where evaluated using isoeugenol as substrate. Agar embedding and zirconium chloride chelation methods resulted in the highest substrate conversion levels. The yields and products of isoeugenol catalysis using Vietnamese crude enzymes/purified Rhus laccase and commercial Denilite laccase were also compared and contrasted with their Chinese lacquer sap equivalents. © 2010 Elsevier B.V.