Adsorption and separation of immunoglobulins by novel affinity core–shell beads decorated with Protein L and l-histidine

Abstract

A novel core shell beaded chromatographic materials was prepared by grafting of glycidyl methacrylate (GMA) on to the surface of poly(hydoxypropyl methacrylate/ethyleneglycol dimethacrylate), p(HPMA/EGDMA) beads via surface-initiated atom transfer radical polymerization (SI-ATRP). For grafting GMA, p(HPMA/EGDMA) beads were first modified with an ATRP initiator. A reaction with 2-bromo-2-methylpropionyl bromide of the hydroxyl groups of the beads led to ATRP initiator-covered surfaces. The grafted p(GMA) fibrous chains on the beads were decorated with two different ligands (i.e., Protein L and l-histidine) for separation of Immunoglobulin's (Igs) from aqueous solution in batch system. The maximum Igs adsorptions on the p(HPMA/EGDMA)-g-p(GMA)-Protein L and p(HPMA/EGDMA)-g-p(GMA)-l-histidine affinity beads were found to be 81.8 and 112.3mg/g at pH 7.5 and 5.5, respectively. The purity of Igs from human serum was analyzed by HPLC. The Protein L immobilized affinity beads provided purity about 98%. The novel core shell polymeric beads decorated with Protein L showed a good selectivity for Igs molecules from diluted human serum. Adsorption studies of Igs onto Protein L and l-histidine immobilized affinity beads were also carried out in a continuous system.