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Protein-imprinted polyacrylamide (PAM)-grafted calcium alginate (CaA) microspheres were synthesized via free-radical grafting polymerization with potassium persulfate and sodium bisulfite as initiators. FTIR, 13C-NMR and SEM were used for characterization. Swelling behaviors were studied and it was found that modified calcium alginate (CaA) microspheres possessed larger swelling degree than calcium alginate, because grafted hydrophilic PAM side chains contributed to more water absorption. Moreover, the durability of the swollen samples was improved for the modified microspheres. Compared with calcium alginate microspheres, modified calcium alginate samples exhibited higher absorption capacity (approximately, 13.1 and 10.3 mg/g) for MIPs in single and binary protein solution. The rebinding selectivity of CaA-g-PAM microspheres (approximately, 2.7) was higher than that of calcium alginate (CaA) microspheres (approximately, 1.5) in binary protein solution. It was suggested that the introduction of PAM side chains was beneficial for the specific recognition of protein. [ABSTRACT FROM AUTHOR]

Bovine serum albumin imprinted polyethylene glycol 600 (PEG600) grafted Calcium alginate (CaA) hydrogel microspheres were prepared and characterized. The adsorption and recognition properties of PEG600 grafted calcium alginate (CaA- g-PEG600) microspheres were evaluated and the results showed that the crosslinking structure of CaA- g-PEG600 microspheres exerted an obvious effect on the adsorption capacity and imprinting properties for bovine serum albumin. The adsorption isotherms and recognition properties indicated that the imprinted modified microspheres had excellent rebinding affinity toward target proteins and the imprinting efficiency varied according to PEG600 grafting degree. The adsorption capacity and the imprinting factor were 5.5 mg g and 3.6, respectively. Adsorption kinetics of CaA- g-PEG600 microspheres in accordance with the molecular weight between crosslinks ( Mc) was investigated and the structural influence on protein selective rebinding was discussed. Furthermore, the binary solution separation performance of CaA- g-PEG600 microspheres with different Mc was investigated by selective binding bovine serum albumin from protein mixture solution. [ABSTRACT FROM AUTHOR]

ABSTRACT Polyethylene glycol grafted calcium alginate hydrogel microspheres are synthesized by ring-opening and addition reaction of epoxy chloropropane. FTIR, 13C NMR, optical microscope, SEM, TG, and DSC are used for characterization. Swelling behaviors are studied and it is found that polyethylene glycol grafted calcium alginate microspheres are improved in anti-swelling properties. Protein-imprinted polyethylene glycol grafted calcium alginate hydrogel microspheres exhibit enhanced specific rebinding quantity (11.16 mg/g) and selective recognition properties (4.71 against BHb), towards target molecule in the presence of competing protein, compared with that of the unmodified samples (4.96 mg/g and 1.75, respectively). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43617. [ABSTRACT FROM AUTHOR]

Vinyl group capped urethane acrylate (UA) was prepared with diisocyanate (IPDI), hydroxyethyl methacrylate (HEMA) and dimethylolpropionic acid (DMPA). The UA was grafted onto sodium alginate via free-radical polymerization with KPS/Na 2 SO 3 as initiator and then crosslinked by Ca 2+ . Grafted polymers (UA- g- CaA) were characterized by FT-IR, SEM, TGA, XRD and tension gauge. The swelling behavior was also investigated. It is found that urethane acrylate grafted calcium alginate possesses lower swelling degree and is improved in thermal stability as well as mechanical performance. The reason is that hydrophobic urethane acrylate provides alginate with physical crosslinking and forms partial crystal regions. The optimum condition for synthesis of UA- g- CaA with lower swelling degree is that weight percentage of initiator to monomer is 0.8%, mass ratio of reductant to oxidant is 0.45:1, monomer concentration is 0.0385 mol/L and grafting reaction temperature is 55 °C. [ABSTRACT FROM AUTHOR]

ABSTRACT Protein-imprinted polyurethane-grafted calcium alginate hydrogel microspheres were prepared and characterized. The samples were investigated with optical microscopy, scanning electron microscopy, 13C-NMR, and Fourier transform infrared spectroscopy. We proved that polyurethane side chains were successfully grafted, and this led to a relatively rough and dense surface. The samples exhibited better swelling durability when applied in specific adsorption tests. The adsorption kinetic and recognition properties indicated that the imprinted modified microspheres had excellent rebinding affinity toward the target proteins. Moreover, the influence of the preassembly pH, rebinding pH, and grafting ratio on the adsorption capacity and imprinting efficiency (IE) were systematically investigated. The study results suggest that the modified samples possessed a higher IE toward the target protein under the optimum pH and grafting ratio. Upon polyurethane grafting modification, the alginate hydrogel microspheres showed improved mechanical stability and recognition specificity. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42140. [ABSTRACT FROM AUTHOR]

Polyurethane grafted calcium alginate hydrogel microspheres intended for bovine serum albumin imprinting were prepared and characterized. The grafting modification was performed prior to the assembling of protein template with hydrogel, which was advantageous to maintain protein conformation and construct more accessible imprinted sites. It was found that the imprinted hydrogel had higher affinity to template molecules after modification. Investigations of grafting ratio influence on specific rebinding and competitive properties indicated that grafted side chains were beneficial to the selective recognition of protein. [ABSTRACT FROM AUTHOR]

Abstract: Polyurethane was synthesized by the reaction of isophorone diisocyanate, 2-hydroxyethyl methacrylate and diethylene glycol. Then polyurethane grafted calcium alginate gel material was prepared via free-radical grafting polymerization with azobisisobutyronitrile as an initiator. Modified calcium alginate hydrogel was improved in thermal property, crystallinity and anti-swelling properties. The reason is that polyurethane side chains affect the arrangement of calcium alginate by forming highly ordered crystal region. [Copyright &y& Elsevier]

Poly vinyl acetate grafted calcium alginate hydrogel microspheres were prepared with bovine serum albumin (BSA) as molecular template. The microspheres exhibited homogeneous and core-shell structure according to different preparation strategy. The rebinding and swelling property of microspheres showed responsiveness toward ionic strength, temperature, and pH. It was found the highest separation factor of 1.85 and imprinting efficiency of 1.75 when the Ca2+ ionic strength was 1.25 and 0.34 mol/kg, respectively. The separation factor was found decreased as temperature grew from 29 to 45°C while the imprinting efficiency reached a peak value at about 37°C. Separation factor of BSA imprinted microspheres at different pH was also recorded and two peaks were found, which were considered to be caused by the similar swollen state due to ionic and covalent crosslinking structure of modified microspheres. The recognition responsiveness is suggested to be influenced by environmental effects due to the changing in imprints' configuration at different swollen states. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]