[Preparation of surface functional magnetic microspheres and their application in nucleic acid separation and enzyme immobilization].
OBJECTIVE
To Prepare surface functional magnetic microspheres for the separation of vascular endothelial growth factor (VEGF) nucleic acid and lactase enzyme immobilization.


METHODS
Using suspension polymerization methods to copolymerize MA-styrene containing magnetite nanoparticles and GMA-styrene also containing magnetite nanoparticles, respectively. Both the carboxyl-modified magnetic microspheres and epoxy-modified magnetic microspheres were obtained. In addition, the chloromethyl-modified magnetic microspheres were prepared by seedy microemulsion. The magnetic microspheres bound with b-gamma IgG were determined by radioimmunoassay (RIA), and the separation of VEGF nucleic acid and lactase enzyme immobilization were performed by carboxyl-modified magnetic microspheres.


RESULTS
Transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS) and infrared (IR) spectra showed that the products of polymer magnetic microspheres were monodispersed and that the magnetic particles were uniformly distributed in the microsphere with special functional group on the surface of the microsphere. RIA showed that three kinds of magnetic microspheres could be bound with b-gamma IgG and the absorption of b-gamma IgG reached 75 micrograms/mg, especially for the carboxyl-modified magnetic microspheres. The carboxyl-modified magnetic microspheres can be used for the separation of VEGF nucleic acid by coupling with corresponding primer. Moreover, the immobilized enzyme was proportional to the amount of the carboxyl-modified magnetic microspheres.


CONCLUSIONS
The surface functional magnetic polymer microspheres can be bound with active bio-substance, and have a wide application prospect in the fields of biology and medicine.
Zhu
Yi-hua
YH
Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237, China. yhzhu@ecust.edu.cn
Wang
Qiang-bin
QB
Gu
Hong-chen
HC
Wang
Sheng-lin
SL
Gao
Feng
F
D000327:Adsorption; D016228:Endothelial Growth Factors / Q000737:chemistry*; D004800:Enzymes, Immobilized; D007074:Immunoglobulin G; D043322:Lactase / Q000378:metabolism; D008280:Magnetics; D008863:Microspheres; D036103:Nanotechnology; D009696:Nucleic Acids / Q000302:isolation & purification*; D010316:Particle Size
D016228:Endothelial Growth Factors; D004800:Enzymes, Immobilized; D007074:Immunoglobulin G; D009696:Nucleic Acids; D043322:Lactase