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Biological Functionality (biological + functionality)
Selected AbstractsDextran Microgels for Time-Controlled Delivery of siRNA,ADVANCED FUNCTIONAL MATERIALS, Issue 7 2008Koen Raemdonck Abstract To apply siRNA as a therapeutic agent, appropriate attention should be paid to the optimization of the siRNA gene silencing effect, both in terms of magnitude and duration. Intracellular time-controlled siRNA delivery could aid in tailoring the kinetics of siRNA gene knockdown. However, materials with easily tunable siRNA release properties have not been subjected to thorough investigation thus far. This report describes cationic biodegradable dextran microgels which can be loaded with siRNA posterior to gel formation. Even though the siRNAs are incorporated in the hydrogel network based on electrostatic interaction, still a time-controlled release can be achieved by varying the initial network density of the microgels. To demonstrate the biological functionality of the siRNA loaded gels, we studied their cellular internalization and enhanced green fluorescent protein (EGFP) gene silencing potential in HUH7 human hepatoma cells. [source] Layer-by-Layer Assembly of Reactive Ultrathin Films Mediated by Click-Type Reactions of Poly(2-Alkenyl Azlactone)s,ADVANCED MATERIALS, Issue 22 2007E. Buck Covalently crosslinked ultrathin films can be fabricated layer-by-layer by exploiting fast and efficient click-type reactions between polyamines and the ,spring-loaded' functionality of poly(2-alkenyl azlactone)s. The accessibility and reactivity of residual azlactone functionality in these ultrathin materials permits further functionalization post-fabrication, suggesting new approaches to the modification, passivation, or patterning of curved or topologically complex surfaces with chemical or biological functionality. [source] Production of ,-Glucosidase and Hydrolysis of Isoflavone Phytoestrogens by Lactobacillus acidophilus, Bifidobacterium lactis, and Lactobacillus casei in SoymilkJOURNAL OF FOOD SCIENCE, Issue 1 2008O.N. Donkor ABSTRACT:, The study determined ,-glucosidase activity of commercial probiotic organisms for hydrolysis of isoflavone to aglycones in fermenting soymilk. Soymilk made with soy protein isolate (SPI) was fermented with Lactobacillus acidophilus LAFTIŽ L10, Bifidobacterium lactis LAFTIŽ B94, and Lactobacillus casei LAFTIŽ L26 at 37 °C for 48 h and the fermented soymilk was stored for 28 d at 4 °C. ,-Glucosidase activity of organisms was determined using ,-nitrophenyl ,-D-glucopyranoside as a substrate and the hydrolysis of isoflavone glycosides to aglycones by these organisms was carried out. The highest level of growth occurred at 12 h for L. casei L26, 24 h for B. lactis B94, and 36 h for L. acidophilus L10 during fermentation in soymilk. Survival after storage at 4 °C for 28 d was 20%, 15%, and 11% greater (P < 0.05) than initial cell counts, respectively. All the bacteria produced ,-glucosidase, which hydrolyzed isoflavone ,-glycosides to isoflavone aglycones. The decrease in the concentration of ,-glycosides and the increase in the concentration of aglycones were significant (P < 0.05) in the fermented soymilk. Increased isoflavone aglycone content in fermented soymilk is likely to improve the biological functionality of soymilk. [source] Characteristic fragmentation of bacteriohopanepolyols during atmospheric pressure chemical ionisation liquid chromatography/ion trap mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 24 2003Helen M. Talbot Bacteriohopanepolyols (BHPs) fragment via characteristic pathways during atmospheric pressure chemical ionisation liquid chromatography/ion trap mass spectrometry (APCI-LC/MSn). Comparison of the MS2 spectra of bacteriohopane-32,33,34,35-tetrol (BHT) and 2, -methylbacteriohopane-32,33,34,35-tetrol has confirmed the previously proposed ring-C cleavage occurring between C-9 and 11 and C-8 and 14. This fragmentation, diagnostic of all hopanoids, also occurs in BHPs containing an amino group (-NH2) at C-35 although the higher relative stability of the ion limits this fragmentation to a minor process after protonation of the basic nitrogen function. Studies of a number of cell cultures including a prochlorophyte (Prochlorothrix hollandica) and a cyanobacterium (Chlorogloeopsis LA) demonstrate the power of this technique to detect composite BHPs with a complex biological functionality at C-35. We also report the first observation of intact pentafunctionalised bacteriohopanepolyols using this method. Copyright Š 2003 John Wiley & Sons, Ltd. [source] Lectin-Based Drug Design: Combined Strategy to Identify Lead Compounds using STD NMR Spectroscopy, Solid-Phase Assays and Cell Binding for a Plant Toxin ModelCHEMMEDCHEM, Issue 3 2010Abstract The growing awareness of the sugar code,i.e. the biological functionality of glycans,is leading to increased interest in lectins as drug targets. The aim of this study was to establish a strategic combination of screening procedures with increased biorelevance. As a model, we used a potent plant toxin (viscumin) and lactosides synthetically modified at the C6/C6, positions and the reducing end aglycan. Changes in the saturation transfer difference (STD) in NMR spectroscopy, applied in inhibition assays, yielded evidence for ligand activity and affinity differences. Inhibitory potency was confirmed by the blocking of lectin binding to a glycoprotein-bearing matrix. In cell-based assays, iodo/azido-substituted lactose derivatives were comparatively active. Interestingly, cell-type dependence was observed, indicating the potential of synthetic carbohydrate derivative to interact with lectins in a cell-type (glycan profile)-specific manner. These results are relevent to research into human lectins, glycosciences, and beyond. [source] | |||||||||||||