Dissertation > Industrial Technology > General industrial technology > Materials science and engineering > Special structural materials

Preparation of Magnetic Composite Microspheres by Template Mini-emulsion Polymerization and Their Application in Protein Purification

Author GongTao
Tutor WangChangChun
School Fudan University
Course Polymer Chemistry and Physics
Keywords Magnetic nanoparticles Chemical precipitation Styrene Template Miniemulsion High magnetic content Monodisperse Magnetic Composite Microspheres Glycidyl methacrylate (GMA) Seeded Emulsion Polymerization Core-shell structure Iminodiacetic acid (IDA) Chelating Protein Purification SDS-PAGE gel electrophoresis
CLC TB383.1
Type PhD thesis
Year 2008
Downloads 643
Quotes 3
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In recent years, organic - inorganic hybrid composite microspheres, especially magnetic composite microspheres being widespread concern. As the inorganic magnetic materials response and the surface of the organic polymer functional magnetic polymer microspheres in the external magnetic field can be convenient, fast and efficient target biomolecule separation from the medium. Display a wide range of applications in the field of biomedical and biochemistry. From the diagnosis the perspective consider ideal magnetic microspheres having a uniform particle size, high magnetic content (rapid magnetic response), functional surface. However, the existing methods of preparation of magnetic composite microspheres either destroyed monodisperse magnetic microspheres, or preparation of single magnetic microspheres dispersed high magnetic content process is too complicated. The prepared magnetic separation carriers there is a low absorption capacity, the coupling efficiency is not higher. To solve the above problems, the paper system around the magnetic composite microspheres, surface functionalization and its application in protein separation and purification commenced mainly achieved the result of the following aspects: 1) magnetic template miniemulsion Preparation of Poly monodisperse, controllable magnetic content of magnetic the composite microspheres Fe 3 O 4 _AT_ Poly (St / DVB), the whole preparation process simple operation, easy to zoom in, the prospects for industrial application. First, by the diameter of phacoemulsification structure uniform magnetic template (magnetic nanoparticle clusters), and then the monomer St and crosslinker DVB was added to the reaction system so that swelling polymerization, by dynamic light scattering (DLS) The results show that the monomers polymerization of the main places in the magnetic template miniemulsion polymerization mechanism is dominated by miniemulsion template miniemulsion. The size of the magnetic composite microspheres prepared a reasonably uniform distribution. DLS characterization results show: to change the amount of the emulsifier can be magnetic composite microspheres particle size in the range of 70-130 nm. By adjusting the magnetic template miniemulsion monomer ratio, can effectively regulate the the magnetic of composite microspheres magnetic content in between 40-70 wt%. Of St / DVB ratio, the amount of emulsifier, co-stabilizers, ultrasonic power, initiator type, the solid content of the magnetic fluid, magnetic fluid with monomer feed ratio of experimental parameters on the performance of magnetic composite microspheres obtained Preparation of magnetic composite microspheres best formula. Prepared magnetic composite microspheres with superparamagnetic, can be used as an excellent magnetic carrier used in the biomedical field. In addition, the proposed template miniemulsion method not only for the preparation of high magnetic content, the monodisperse magnetic composite microspheres, and can be as high encapsulation efficiency inorganic - organic hybrid microspheres. 2) the Magnetic Fe 3 O 4 _AT_ Poly (St / DVB) composite microspheres seed by seed emulsion polymerization surface rich epoxy functional groups The core-shell magnetic Fe 3 O 4 / Poly (St / DVB) @ Poly (GMA / DVB) composite microspheres. TEM electron microscopy results show that the core-shell magnetic composite microspheres particle size distribution is very uniform. The magnetic content of the core-shell magnetic composite microspheres controllable by adding different amounts of shell monomer, 23-43 wt%. Sodium thiosulfate titration core-shell magnetic composite microspheres surface epoxy group of 0.126-0.190 mmol / g. Iminodiacetic acid (IDA) with the epoxy group of the surface of the magnetic composite microspheres ring opening reaction, IDA metal ion chelating group introduced in the surface of the magnetic composite microspheres was prepared by magnetic affinity separation of the chelated metal ion carrier. Atomic absorption spectrometry (AAS) and by ultraviolet spectroscopy (UV) analysis results show that the ability of the magnetic composite vector chelated Cu 2 of 0.068-0.072 mmol / g and 0.091-0.110 mmol / g, respectively. 3) the core-shell magnetic separation vector Fe 3 O 4 / Poly (St-DVB) @ Poly (GMA-DVB)-IDA-Ni 2 < / sup> applied to separation and purification of S-adenosylmethionine synthetase (SAMS). Under the applied magnetic field, the magnetic carrier can be easily and rapidly purified the SAMS. Detailed study of the reaction medium by the initial the SAMS protein concentration imidazole eluent concentration, reaction medium ionic strength (NaCl concentration), the influence of the pH value, the chelated metal ion species and other purification conditions of protein separation and purification, to thereby obtain the magnetic microspheres purified SAMS protein separation conditions. Finally, the different initial concentrations of the SAMS protein was purified under optimal separation conditions, the results show that when the initial protein concentration of 3.0 mg / mL, the amount of protein purification was 50.0 mg / g, and SDS-PAGE electrophoresis result shows the purified The high purity of the protein, no contaminating proteins.

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