Immunoglobulin G purification from bovine serum with pseudo-specific supermacroporous cryogels

•Bovine IgG purification from direct whole serum with supermacroporous cryogels.•Gaining pseudospecificity to cryogels by N-vinylimidazole incorporation.•The best adsorption of bovine IgG was observed at pH 7.4 up to 21.13 mg/g.•Describing the adsorption process by mathematical models.•Investigation of the purification efficiency and IgG purity with SDS–PAGE study.

Supermacroporous cryogels were synthesized and used for the purification of immunoglobulin G (IgG) from bovine serum. Imidazole functional groups were incorporated into basic polymeric backbone to gain pseudo-specificity to cryogels by using n-vinylimidazole as comonomer. The cryogels were prepared in aqueous solution of monomers partially frozen inside plastic syringe column by cryogelation. Poly(2-hydroxyethyl methacrylate-n-vinylimidazole) [poly(HEMA-VIM)] cryogels were prepared by polymerization of water-soluble functional monomer, n-vinylimidazole, with basic monomer HEMA. The characterization methods including swelling test, Fourier transform infrared spectroscopy (FTIR), elemental analysis, and scanning electron microscopy (SEM) were performed to evaluate physical and chemical properties of cryogels prepared. Bovine IgG adsorption on plain and composite cryogels was studied with respect to different parameters such as, pH, IgG concentration, flow rate, ionic strengths, and adsorption time. The best adsorption of bovine IgG was observed at pH 7.4 up to 21.1 mg per unit mass of poly(HEMA-VIM) cryogel. Elution of IgG adsorbed from the cryogels was easily achieved with 0.1 M acetate buffer containing 1 M NaCl at pH 4.0. In order to describe the adsorption process, we applied some equilibrium and kinetic adsorption models to the data. The results best fitted to Langmuir model showing monolayer protein adsorption and surface homogeneity of cryogel. Finally, we evaluated IgG purification from bovine serum under optimal condition determined. The purification efficiency and IgG purity were investigated with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS–PAGE) study.