Dalsgaardlaustsen7687

A facile method was developed to produce porous alginate beads (PABs) with a controllable interconnected porous structure with aqueous two phase (ATPS) emulsions as template for 3D cell culture. ATPS emulsions, containing two biocompatible immiscible aqueous phases of cell/dextran (Dex) mixture and alginate (Alg)/polyethylene glycol (PEG) mixture and stabilized by mPEG-BSA particles, were introduced to form PABs. The pore size of PABs could be controlled by changing the emulsification frequency and the volume ratio between the ATPS emulsions and PEG-Alg solution. Moreover, cells could be directly encapsulated in the interconnected pores due to the excellent biocompatibility of ATPS. HeLa and human liver cancer cells encapsulated in the PABs present stronger cell activity (>95 %), proliferation, and enhanced functions compared with the cells encapsulated in general alginate beads (GABs). It is believed that the PABs is a promising microcarriers for 3D cell culture in vitro.Sea urchin possesses both high nutritional and medicinal value. It contains diverse biological active polysaccharides. But there are few studies on its glycogen. In the current study, a glucan (MSGA) was separated from Strongylocentyotus internedius and purified by ion exchange and gel filtration column. Chemical analysis revealed that MSGA with 2.65 × 107 Da is made up entirely of glucose. The analysis of methylation, NMR and mass spectrum demonstrated that MSGA is a highly branched glycogen with α-(1→4) linked gluconic backbone and branched at C-6 (one branch per five residues). In addition, MSGA showed good in vitro immunostimulatory activity via NF-κB and MAPKs pathways. It is considered that high degree of branching is necessary for its activity. read more However, the relationship between structure and immunostimulatory activity of natural glycogens is difficult to elucidate because the difference in their structural properties. Therefore, much more research is needed in this area.An immuno-stimulatory polysaccharide (EtISPFa) was purified from water extract of the fungus Echinodontium tinctorium. EtISPFa has an estimated weight average molecular weight (Mw) of 1354 kDa and is composed of glucose (66.2 %), glucuronic acid (10.1 %), mannose (6.7 %), galactose (6.4 %), xylose (5.6 %), rhamnose (3.1 %), fucose (1.8 %), and arabinose (0.2 %). It has multiple glycosidic linkages, with 3-Glcp (19.8 %), 4-GlcpA (10.8 %), 6-Glcp (10.7 %), and 3,6-Glcp (8.7 %) being the most prominent. NMR analysis showed that EtISPFa has a backbone containing mostly of 3-substituted β-glucopyranose with 4-substituted glucopyranosyluronic acid. Short side chains consisting of an average of two β-glycopyranose residues, connected through 1→6 linkages, are attached to the 6-position of about every 4th or 5th backbone glucose residue. EtISPFa is a novel glucuronic acid-containing β-glucan capable of significantly inducing the production of cytokines IL-17, IL-16, MIP-2, G-CSF,GM-CSF, LIF, MIP-1α, MIP-1β, and RANTES in vitro. EtISPFa should be further explored for its immuno-stimulatory activity in vivo.Herein, we present a study on the catalytic evaluation of biocompatible chitosan-stabilized gold nanoparticles (CH-AuNPs) on the oxidation of morin as a model reaction. Biocompatible CH-AuNPs have been characterized through several analytical methods such as TEM, UV-vis, DLS and zeta potential analyses. CH-AuNPs have a small size (10 ± 0.4 nm) with a narrow size distribution and high positive surface charge (+40.1 mV). CH-AuNPs has been demonstrated to be highly active nanocatalysts for the oxidation of morin with the assistance of H2O2 as an oxidant compared with control experiments. The oxidation reaction follows a pseudo-first-order reaction. The kinetic studies show that apparent rate constant (kapp) is positively correlated with the concentrations of CH-AuNPs and H2O2, while it is negatively correlated with morin concentration. Furthermore, the reusability tests have been performed and the results demonstrate the long-term stability and reusability of CH-AuNPs without any loss of catalytic activity. Cytotoxicity studies exhibit that CH-AuNPs have low toxicity and they are biocompatible with HeLa and MCF-7 cells.To investigate the effects of interactions between cellulose and xyloglucan (XG) on in vitro fermentation, a composite of bacterial cellulose (BC) incorporating XG during pellicle formation (BCXG), was fermented using a human faecal inoculum, and compared with BC, XG and a mixture (BC&XG) physically blended to have the same BC to XG ratio of BCXG. Compared to individual polysaccharides, the fermentation extent of BC and fermentation rate of XG were promoted in BC&XG. XG embedded in the BCXG composite was degraded less than in BC&XG, while more cellulose in BCXG was fermented than in BC&XG. This combination explains the similar amount of short chain fatty acid production noted throughout the fermentation process for BCXG and BC&XG. Microbial community dynamics for each substrate were consistent with the corresponding polysaccharide degradation. Thus, interactions between cellulose and XG are shown to influence their fermentability in multiple ways.Oligosaccharides and polysaccharides constitute the principal components of carbohydrates, which are important biomacromolecules that demonstrate considerable bioactivities. However, the variety and structural complexity of oligo/polysaccharides represent a major challenge for biological and structural explorations. To access structurally defined oligo/polysaccharides, biological strategies using glycoenzyme biocatalysts have shown remarkable synthetic potential attributed to their regioselectivity and stereoselectivity that allow mild, structurally controlled reaction without addition of protecting groups necessary in chemical strategies. This review summarizes recent biotechnological approaches of oligo/polysaccharide synthesis, which mainly includes in vitro enzymatic synthesis and cell factory synthesis. We have discussed the important factors involved in the production of nucleotide sugars. Furthermore, the strategies established in the cell factory and enzymatic syntheses are summarized, and we have highlighted concepts like metabolic flux rebuilding and regulation, enzyme engineering, and route design as important strategies.