A new specific metal ion chelated-poly(N-vinylimidazole) gel sorbents for albumin adsorption-desorption

Poly (N-vinylimidazole) (PVIm) hydrogels were prepared by gamma -irradiatin g binary mixtures of N-vinylimidazole-water in a Co-60-gamma source having 4.5 kGy/h dose rate. These affinity gels having different swelling ratio of Cu(II)chelated, Co(II)-chelated and plain PVIm in acetate buffer were used in the albumin adsorption studies. Bovine serum albumin (BSA) adsorption o n these gels from aqueous solutions containing different amounts of BSA at different pH adjusted with acetate and phosphate buffer was investigated in batch reactors. The adsorption capacities of BSA on/in the gels were decre ased dramatically by increasing the ionic strength CI) adjusting with NaCl. BSA adsorption capacities of the metal ion-chelated gels were higher than the plain PVIm gel even if the swelling ratio of the metal ion-chelated gel s was very low comparing to the PVIm gel. The rigidity of the metal ion-che lated gel is very high and it can be used for the column applications. More than 95% of BSA were desorbed in 3 h in the desorption medium containing K SCN for PVIm gel. and EDTA for metal ion-chelated gels. These results indic ate that PVIm and metal ion-chelated PVIm gels are very efficient to remove BSA and the different metal ion-chelated PVIm gels show different affinity for BSA or biomolecules.