Adsorption of BSA onto radiation-crosslinked poly (AAm/HPMA/MA) terpolymers

Abstract

Summary The terpolymeric poly(acrylamide/2-hydroxypropylmethacrylate/maleic acid) (AAd HPMAIMA) hydrogels in the rod form have been prepared by y-radiation of quaternary mixtures of acrylamide, 2-hydroxy propylmethacrylate, maleic acid and water. The hydrogels were used in experiments on swelling, diffusion and adsorption of bovine serum albumin (BSA) from aqueous BSA solutions. In the experiment of BSA adsorp-tion, the effect of initial concentration of BSA, content of MA, irradiation doses and medium pH on the adsorption efficiency of the hydrogel were studied. The binding of BSA onto AAm/HPMA/MA hydrogel corresponds to L4-type (Langmuir type with two layers) adsorption isotherms in the Giles classification system for adsorption of a solute from its solution The maximum adsorption capacity of monolayer adsorption (Q,,l,,J and the binding constant were found to be 1.27 ing BSA (g gel)" and 67.9 L (mg BSA).', respectively. The adsorption of BSA within AAm/€€PMNMA hydrogels increased with the increase in MA content in the AAm/HPMA/MA hydrogels. When the irradiation doses of hydrogel increased the adsorption of BSA also increased. The maximum adsorption of BSA was observed at pH 3.7. Significant amount of the adsorbed BSA (up to 95%) was eluted in the elution medium containing 1.0 M NaSCN at pH 8.0.