A Novel Method To Prepare Magnetic Polymer-Based Anion Exchangers And Their Application

Magnetic microspheres with ion-exchange features were prepared by applying a swelling and penetration process using polystyrene-divinylbenzene-based anion-exchange resins as starting materials. The polymeric anion-exchange particles were swollen with an aqueous solution of N-methyl-2-pyrrolidone, followed by incubation with superparamagnetic iron oxide nanoparticles to allow them to penetrate into the swollen particles. The pH value in the solution of magnetic nanoparticles could significantly influence the uptake of magnetic nanoparticles by the swollen anion-exchange particles. Higher amounts of magnetic nanoparticles entrapped within anion exchangers could be achieved at pH 10-12. An increase in the concentration of magnetic nanoparticles led to a higher density of magnetic nanoparticles entrapped within the interior of anion exchangers and, thus, higher magnetization of the magnetic anion exchangers. Loading of the magnetic nanoparticles onto the exchanger had no effect on anion-exchange functionality. The utility of the resulting magnetic anion-exchange resins was demonstrated for the isolation of plasmid pEGFP-C1 from Escherichia coli cell lysates. The magnetic anion-exchange microspheres could be easily collected within a few seconds in a magnetic field. Thus, automation of the protocol for DNA isolation using these magnetic anion-exchange resins has a high potential. (C) 2014 Wiley Periodicals, Inc.