Abstract
Heparin immobilized poly(2-hydroxylethyl methacrylate) PHEMA cryogel was synthesized and applied for lysozyme purification from egg white. Firstly, the PHEMA cryogel was synthesized by cryopolymerization and then heparin was covalently immobilized on to the PHEMA cryogel with cyanogen bromide activation. The modification of PHEMA cryogel structure with heparin was further confirmed by Fourier-transform infrared spectroscopy (FTIR). The surface and inner structure morphologies of PHEMA cryogels were studied and characterized by the scanning electron microscope (SEM). The surface area of PHEMA cryogel was found to be 25.2 m2/g. Heparin immobilized PHEMA cryogels were used in lysozyme adsorption studies to assess the effects of pH, lysozyme concentration, flow rate, temperature and ionic strength. The maximum lysozyme adsorption on the heparin immobilized PHEMA cryogel was found to be 48.73 mg/g from aqueous solutions under optimized conditions. 1.0 M NaCI solution was used for desorption of lysozyme in a continuous system. The reusability of heparin immobilized PHEMA cryogels was tested for 10 adsorption-desorption cycles. The Langmuir adsorption model was plotted and found fitted for adsorption studies. The purity of lysozyme from egg white studies was analysed by sodium-dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) using 12% separating gel.