Preparation of Fe III -Chelated Poly HEMA-MAH Cryogel for Lysozyme Adsorption

Abstract

Poly 2-hydroxyethyl methacrylate-N-methacryloyl- L -histidine methyl ester [poly HEMA-MAH ] cryogel was preparedby bulk polymerization which proceeds in an aqueous solution of monomers frozen inside a glass column cryo-polymerization . After thawing, the monolithic cryogel contains a continuous polymeric matrix having interconnected poresof 10-50 μm size. Then the monolithic cryogel was loaded with Fe III ions to form the metal chelate with poly HEMAMAH cryogel. Poly HEMA-MAH cryogel was characterized by swelling studies, FTIR, scanning electron microscopy,and elemental analysis. The equilibrium swelling degree of the poly HEMA-MAH monolithic cryogel was 2.82 g H2O/gcryogel. Poly HEMA-MAH cryogel containing 36.4 μmol MAH/g was used in the adsorption/desorption of lysozymefrom aqueous solutions. The nonspecific adsorption of lysozyme was very low 1.1 mg/g . The maximum amount oflysozyme adsorption from aqueous solution in phosphate buffer was 40.7 mg/g at pH 7.0. It was observed thatlysozyme could be repeatedly adsorbed and desorbed with the poly HEMA-MAH cyogel without significant loss ofadsorption capacity