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Abstract: With the aim of improving the performance of calcium alginate (Ca-Alg) hydrogel, a small quantity (5% of dry mass of sodium alginate) of hydroxyethyl cellulose (HEC) was used to associate sodium alginate to form interpenetrating networks (IPNs). Swelling results and mechanical stability tests showed that the formation of IPNs considerably restrained dried samples from swelling in 0.9% sodium chloride aqueous solution and reinforced the mechanical strength of microspheres. For emulsion droplets as template, microscopy showed that the original emulsion templating method employed in preparation of macroporous Ca-Alg microspheres was also applicable in the IPNs system. As for bovine serum albumin molecules as template, Alg/HEC microspheres showed a better recognition effect than that of Ca-Alg microspheres. The reduced network mesh size and strengthened cross-linkages in IPNs are responsible for these results. [Copyright &y& Elsevier]

Abstract: Calcium phosphate/alginate hybrid polymer microspheres with bovine serum albumin (BSA) embedded and coated on the surface were prepared with sodium alginate (SA) and (NH4)2HPO4 by using CaCl2 as the gelling agent in an inverse suspension. The morphology and pore structure of imprinted hybrid polymer microspheres was observed by optical microscopy, ESEM, TEM and SEM. Infrared spectrum analysis demonstrated that new hybrid components were produced in the polymer microspheres. Rebinding dynamic and thermodynamic behaviors of the two imprinted microspheres were evaluated, resulting in a higher BSA affinity for imprinted microspheres relative to non-imprinted ones. The factors influencing the imprinting efficiency (IE) of imprinted microspheres were also studied, including the concentration of CaCl2, template content and pH in rebinding solution, etc. All the results indicated that the surface imprinted microspheres exhibited better imprinting efficiency and higher rebinding capacity. Selectivity tests showed that the imprinted beads exhibited good recognition properties for the template protein versus others. [Copyright &y& Elsevier]