Synthesis and characterization of macroporous poly(acrylamide methacrylamido histidine) cryogels and their use in antibody purification

Abstract

Poly(acrylamide-methacrylamidohistidine) [poly(AAm-MAH)] cryogel was prepared by bulk polymerization which proceeds in aqueous solution of monomers frozen inside a syringe column (cryo-polymerization). After thawing, the monolithic cryogel contains a continuous polymeric matrix having interconnected pores of 10-100 μm size. Poly(AAm-MAH) cryogel was characterized by swelling studies, FTIR and scanning electron microscopy. The equilibrium swelling degree of the poly(AAm-MAH) monolithic cryogel was 6.97 g H2O/g cryogel. Poly(AAm-MAH) cryogel was used in the adsorption/desorption of immunoglobulin G (IgG) from aqueous solutions and human plasma. The non-specific adsorption of IgG was very low (0.22 mg/g). The maximum amount of IgG adsorption from aqueous solution in HEPES buffer was 32.879 mg/g at pH 7.4. Higher IgG adsorption value was obtained from human plasma (up to 100 mg/g). Desorption of IgG from poly(AAm-MAH) cryogel was obtained using 20 mM Acetate buffer containing 1.0 M NaCl at pH 4. It was observed that IgG could be repeatedly adsorbed and desorbed with poly(AAm-MAH) cryogel without significant loss in the adsorption capacity.