Synthesis of Cibacron Blue F3GA-coupled magnetic PMMA nanospheres and their use for protein affinity separation

BACKGROUND: New magnetic carrier separation technologies, capable of treating dilute solutions in large-scale processes, even in the presence of biological debris, are necessary for the future development of biotechnology. Non-porous magnetic carriers are more resistant to fouling, show better mass transfer and have lower non-specific adsorption than porous carriers. Nanosized magnetic carriers have a surface area comparable to that of typical macroporous resins, and therefore their application has advantages. RESULTS: Magnetic poly(methyl methacrylate) (PMMA) nanospheres with an average diameter of 76 nm and narrow size distribution were prepared by a facile mini-emulsion polymerization. After surface modification with poly(ethylene glycol), Cibacron Blue F3GA (CB) was coupled to the magnetic PMMA nanospheres to form dye ligand-attached magnetic adsorbents for bovine serum albumin (BSA) adsorption. The CB-coupled magnetic PMMA nanospheres showed very high adsorption capacity (1121.98 mg g(-1)) and little non-specific adsorption for BSA. The adsorbed protein could be easily desorbed using high ionic strength solution. CONCLUSION: The CB-coupled magnetic PMMA nanospheres showed a high BSA adsorption capacity, low non-specific adsorption and fast adsorption kinetics in comparison with other dye-affinity adsorbents. These characteristics indicate that these magnetic PMMA nanospheres have great potential for protein affinity separation and purification. (C) 2009 Society of Chemical Industry