Histidine Containing Macroporous Affinity Cryogels for Immunoglobulin G Purification

A supermacroporous cryogel was prepared to obtain an efficient and cost effective purification of IgG from human plasma. N-methacryloyl-(L)-histidine methyl ester (MAH) was chosen as the pseudospecific ligand and/or comonomer. Poly(hydroxyethyl methacrylate-N-methacryloyl-(L)-histidine methylester) [PHEMAH] cryogel was produced by free radical polymerization initiated by N,N,N',N'-tetramethylene diamine (TEMED) and ammonium persulfate (APS) pair in an ice bath. PHEMAH cryogel had a specific surface area of 38.6 m(2)/g. PHEMAH cryogel was characterized by swelling studies, scanning electron microscopy and elemental analysis. PHEMAH cryogel containing 113.7 mu mol MAH/g was used in the purification of IgG from human plasma. Compared with the poly(hydroxyethyl methacrylate) (PHEMA) cryogel (0.4 mg/g), the IgG adsorption capacity of the PHEMAH cryogel (24.7 mg/g) was improved significantly due to the MAH incorporation into the polymeric matrix. The maximum amount of IgG adsorption from aqueous solution in phosphate buffer was observed at pH 7.4. The IgG adsorption amount from human plasma was 97.3 mg/g with a purity of 94.6%. It was observed that IgG could be repeatedly adsorbed and eluted with PHEMAH cryogel without significant loss in the adsorption capacity.