New Monodisperse Magnetic Polymer Microspheres Biofunctionalized for Enzyme Catalysis and Bioaffinity Separations

Abstract

Magnetic macroporous PGMA and PHEMA microspheres containing carboxyl groups are synthesized by multi-step swelling and polymerization followed by precipitation of iron oxide inside the pores. The microspheres are characterized by SEM, IR spectroscopy, AAS, and zeta-potential measurements. Their functional groups enable bioactive ligands of various sizes and chemical structures to couple covalently. The applicability of these monodisperse magnetic microspheres in biospecific catalysis and bioaffinity separation is confirmed by coupling with the enzyme trypsin and huIgG. Trypsin-modified magnetic PGMA-COOH and PHEMA-COOH microspheres are investigated in terms of their enzyme activity, operational and storage stability. The presence of IgG molecules on microspheres is confirmed.

PEGylation of magnetic poly(glycidyl methacrylate) microparticles for microfluidic bioassays

“…Magnetic poly(glycidyl methacrylate) (PGMA) microspheres containing carboxyl groups (PGMA-COOH) were prepared according to a previously described procedure 36 by multistep swelling and a polymerization method based on polystyrene latex seeds. The seeds were activated with dibutyl phthalate to enable subsequent swelling with monomers (glycidyl methacrylate, ethylene dimethacrylate, and [2-(methacryloyloxy)ethoxy]acetic acid) and a porogen (cyclohexyl acetate).…”

“…The particles were obtained by multistep swelling and polymerization 36 There exist several strategies for introducing PEG onto the surface of particles, namely, physisorption, "grafting to" and "grafting from" 14,15 . Although the "grafting from" strategy enables immobilization of PEG with high grafting density, the "grafting to" approach was chosen for this study as it is less elaborate and time-consuming while providing complete coating of the microspheres.…”

“…These properties include (i) minimal NSA of molecules from complex biological mixtures, (ii) stability against aggregation of particles under various conditions, (iii) minimal adhesion of particles on inner walls of microfluidic devices and tubes, and (iv) satisfactory magnetic response when inserted into a magnetic field. In this study, new poly(glycidyl methacrylate) microspheres containing carboxyl groups (PGMA-COOH) were prepared by a multistep swelling and polymerization 36 originally developed for polystyrene microspheres 37 . The particles were subsequently functionalized by PEG.…”

Incorporation of iron oxide nanoparticles into temperature-responsive poly (N-isopropylacrylamide-co-acrylic acid) P (NIPAAm-AA) polymer hydrogel

“…Magnetic iron oxide nano/micro particles have become potential in biomedical field because of their wide range of applications such as in controlled delivery [1], DNA separation [2], protein adsorption [3] and catalysis [4,5]. The main advantage of these magnetic particles is easy to guide by applying external magnetic field during application.…”

Novel Approach to Synthesis of Monodisperse Polymeric Microspheres: Heterophase Polymerization of Styrene and Methyl Methacrylate in Presence of Water-Insoluble Functional PDMSs

“…Over the recent years monodisperse functional polymeric microspheres have been extensively studied and widely used as the protein carriers for the development of immunodiagnostic assays; the insoluble supports in solid-phase peptide synthesis; in nanotechnology as building blocks for the new types of materials, including solid spatially periodic structures with nonlinear optical properties; as the stationary phases for chromatography and catalysis and so forth [1][2][3][4].…”