Antibody purification with protein A attached supermacroporous poly(hydroxyethyl methacrylate) cryogel

Immunoglobulin G (IgG) Purification from human plasma with protein A attached supermacroporous poly(hydroxyethyl methacrylate) [PHEMA] cryogel has been studied. PHEMA cryogel was prepared by bulk polymerization which proceeds in aqueous solution of monomer frozen inside a plastic syringe (cryo-polymerization). After thawing, the PHEMA cryogel contains a Continuous matrix having interconnected pores of 10-200 mu m size. Protein was covalently attached onto the PHEMA cryogel via cyanogen bromide (CNBr) activation. The maximum IgG adsorption oil the PHEMA/protein A cryogel Was found to be 83.2 mg/g at pH 7.4 from aqueous Solutions. The non-specific IgG adsorption onto the PHEMA cryogel was about 0.38 mg/g. The macropore size of the cryogel makes it possible to process blood cells without blocking the Column. Higher adsorption capacity was observed from human plasma (Lip to 88.1 mg/g). Adsorbed IgG was eluted using 0.1 M glycine-HCl buffer (pH 3.5) with a purity of 85%. PHEMA-protein A cryogel was used for repetitive adsorption/desorption of IgG without noticeable loss in IgG adsorption capacity after 10 cycles. PHEMA-protein A cryogel showed several advantages Such as simpler preparation procedure, good selectivity for IgG Purification from human plasma and good stability throughout repeated adsorption-desorption cycles. (C) 2009 Elsevier B.V. All rights reserved.