title: Silane-modified magnetic beads: application to immunoglobulin G separation.
abstract: The magnetic poly(2-hydroxyethyl methacrylate ethylene glycol dimethacrylate) [m-poly(HEMA-EGDMA)] beads (150-250-microm diameter in spherical form) were prepared by a radical suspension polymerization technique. The pseudo-specific ligand, reactive imidazole containing 3-(2-imidazoline-1-yl)propyl (triethoxysilane) (IMEO) was selected as a silanization agent. IMEO was covalently immobilized onto the magnetic beads. IMEO-immobilized m-poly(HEMA-EGDMA) beads were used for the affinity adsorption of immunoglobulin-G (IgG) from aqueous solutions and human plasma. To evaluate the degree of IMEO attachment, the m-poly(HEMA-EGDMA) beads were subjected to Si analysis by using flame atomizer atomic absorption spectrometer, and it was estimated as 36.6 mg IMEO/g of polymer. The nonspecific IgG adsorption onto the plain m-poly(HEMA-EGDMA) beads was very low (about 0.4 mg/g). Higher adsorption values (up to 55 mg/g) were obtained when the m-poly(HEMA-EGDMA)/IMEO beads were used from both aqueous solutions and human plasma. The maximum IgG adsorption on the m-poly(HEMA-EGDMA)-IMEO beads was observed at pH 7.0. The IgG molecules could be repeatedly adsorbed and desorbed with m-poly(HEMA-EGDMA)-IMEO beads without noticeable loss in the IgG adsorption capacity. The adsorption capacity from human plasma in magnetically stabilized fluidized bed decreased drastically from 78.9 to 19.6 mg/g with the increase of the flow rate from 0.2 to 3.5 mL/min.
authors.affiliation: Chemistry Department, Adnan Menderes University, Aydin, Turkey.
authors.forename: Nevra
authors.initials: N
authors.lastname: Oztürk
authors.forename: M Emin
authors.initials: ME
authors.lastname: Günay
authors.forename: Sinan
authors.initials: S
authors.lastname: Akgöl
authors.forename: Adil
authors.initials: A
authors.lastname: Denizli
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D002846:Chromatography, Affinity / Q000379:methods*; D007074:Immunoglobulin G / Q000276:immunology / Q000302:isolation & purification*; D018189:Immunomagnetic Separation / Q000379:methods*; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D008863:Microspheres; D012821:Silanes / Q000737:chemistry*