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High Binding Capacity (high + binding_capacity)
Selected AbstractsA Novel Approach to Magnetic Nanoadsorbents with High Binding Capacity for Bovine Serum AlbuminMACROMOLECULAR RAPID COMMUNICATIONS, Issue 3 2007Yabin Sun Abstract Magnetic nanoadsorbents using Fe3O4 nanoparticles as cores and poly(methyl acrylic acid) (PMAA) as ionic exchange groups were prepared through our novel approach. Two steps were involved in this approach: the first was to functionalize the magnetic nanoparticles (MNPs) with methacrylate double bonds via the combination of ligand exchange and condensation of methacryloxypropyltrimethoxysilane(MPS); the second was to graft PMAA chains onto the surface of MNPs through radical polymerization. The success of the various surface functionalization steps was ascertained using FTIR and XPS. The as-synthesized PMAA-coated MNPs were effective in binding bovine serum albumin (BSA) with a high capacity of 1,300 mg,·,g,1. [source] Photopolymerizable Hydrogels Made from Polymer-Conjugated Albumin for Affinity-Based Drug Delivery,ADVANCED ENGINEERING MATERIALS, Issue 1-2 2010Liat Oss-Ronen As a drug delivery vehicle, biodegradable albumin hydrogels can combine the high binding capacity of albumin with the structural stability of a polymeric hydrogel network to enable controlled release of small molecules based on both binding affinity and physical interactions. In the present study, we report on the development of a hybrid hydrogel composed of albumin conjugated to poly(ethylene glycol) (PEG) for drug delivery applications where controlled release is accomplished using the natural affinity of the drugs to the serum albumin. Bovine serum albumin was conjugated to PEG-diacrylate having a molecular weight of 1.5, 4, or 10,kDa to form a PEGylated albumin macromolecule (mono-PEGylated or multi-PEGylated). Biodegradable hydrogels were formed from the PEGylated albumin using photopolymerization. Two model drugs, Warfarin and Naproxen, were used for equilibrium dialysis and release experiments from the hydrogels, both having relatively low molecular weights and a known high affinity for albumin. Equilibrium dialysis experiments showed that multi-PEGylation of albumin significantly decreased the drug affinity to the protein compared to non-PEGylated controls, irrespective of the PEG molecular weight. However, the results from drug release experiments showed that mono-PEGylation of albumin did not change its natural affinity to the drug. Comparing the release profiles with a Fickian diffusion model provided strong evidence that hydrogels containing mono-PEGylated albumin exhibited sub-diffusive drug release properties based on the affinity of the drug to the tethered protein. [source] Preparation and Characteristics of Esculin-Imprinted PolymersHELVETICA CHIMICA ACTA, Issue 6 2007Guo-Song Wang Abstract Four molecularly imprinted polymers (MIPs) were prepared in MeOH with esculin (=6,7-dihydroxycoumarin 6-(, - D -glucopyranoside)=6-(, - D -glucopyranosyloxy)-7-hydroxy-2H -1-benzopyran-2-one) as the imprinted molecule, methacrylic acid (=2-methylprop-2-enoic acid; MAA), acrylamide (=prop-2-enamide; AM), 4-vinylpyridine (=4-ethenylpyridine; 4-VP), or 2-vinylpyridine (=2-ethenylpyridine; 2-VP) as the functional monomer, respectively, as well as ethylene glycol dimethacrylate (=2-methylprop-2-enoic acid ethane-1,2-diyl ester; EGDMA) as the cross-linking agent. The interaction between the template and the functional monomers was investigated by fluorescence and UV spectrophotometry, respectively, which revealed the presence of esculin/monomer complexes in the stoichiometric ratio 1,:,2 in the pre-polymerization mixture. The resultant polymers were studied in equilibrium binding experiments to evaluate the recognition ability and the binding capacity towards esculin. The results showed that MIP1, prepared with MAA as the functional monomer, exhibited advantageous characteristics of high binding capacity, optimal imprinting effect, and good selectivity towards esculin. The Scatchard analysis indicated that there are two types of binding sites in MIP1, and its binding parameters including the apparent maximum numbers of binding sites and the dissociation constants were calculated. Finally, by packing an SPE column (SPE=solid-phase extraction) with MIP1, the esculin was separated and enriched successfully by this sorbent from samples of Cortex fraxini, and the average recovery was up to 74.7%. [source] Humic acid metal cation interaction studied by spectromicroscopy techniques in combination with quantum chemical calculationsJOURNAL OF SYNCHROTRON RADIATION, Issue 2 2010M. Plaschke Humic acids (HA) have a high binding capacity towards traces of toxic metal cations, thus affecting their transport in aquatic systems. Eu(III),HA aggregates are studied by synchrotron-based scanning transmission X-ray microscopy (STXM) at the carbon K -edge and laser scanning luminescence microscopy (LSLM) at the 5D0,7F1,2 fluorescence emission lines. Both methods provide the necessary spatial resolution in the sub-micrometre range to resolve characteristic aggregate morphologies: optically dense zones embedded in a matrix of less dense material in STXM images correspond to areas with increased Eu(III) luminescence yield in the LSLM micrographs. In the C 1s -NEXAFS of metal-loaded polyacrylic acid (PAA), used as a HA model compound, a distinct complexation effect is identified. This effect is similar to trends observed in the dense fraction of HA/metal cation aggregates. The strongest complexation effect is observed for the Zr(IV),HA/PAA system. This effect is confirmed by quantum chemical calculations performed at the ab initio level for model complexes with different metal centres and complex geometries. Without the high spatial resolution of STXM and LSLM and without the combination of molecular modelling with experimental results, the different zones indicating a `pseudo'-phase separation into strong complexing domains and weaker complexing domains of HA would never have been identified. This type of strategy can be used to study metal interaction with other organic material. [source] Tartaric Acid Starch Ether: A Novel Biopolymer-Based PolyelectrolyteMACROMOLECULAR RAPID COMMUNICATIONS, Issue 16 2003Carsten Grote Abstract New tartaric acid starch ethers have been synthesized applying starch sources of different amylose content. The reactions were carried out heterogeneously in ethanol/water mixtures with cis -disodiumepoxysuccinate as etherifying reagent leading to products of a degree of substitution (DS) up to 0.3. The molecular structure of the new starch ethers was evaluated by elemental analysis, FTIR and 13C NMR spectroscopy. Preliminary studies using a convenient titration method indicate a high binding capacity for Ca2+ ions which is dependent on the starch source and DS. Tartaric acid starch ethers. [source] | |||||||||||||