| 摘要 |
Spherically shaped polyvinyl alcohol (PVAL) polymer particles are prepared encapsulating a magnetic colloid that provides the particles with magnetic properties for use in binding biomolecules. The particles have a size of 1-10 mum that makes them particularly suitable for use in cell separation/sorting, cleaning biosubstances in suspension and diagnostic assays. The particles are prepared by dispersing a magnetic colloid containing a magnetic material such as a ferromagnetic or superparamagnetic substance in an aqueous solution of polyvinyl alcohol containing reactive hydroxyl groups, adding the resultant mixture to an organic phase containing a mixture of at least two emulsifiers, and adding a water-soluble cross-linking agent such as a dialdehyde that reacts with the hydroxyl groups of polyvinyl alcohol to form the polymer particles. The emulsifiers are miscible in the polyvinyl alcohol solution, and at least one emulsifier is semi-hydrophilic and at least one emulsifier is lipophilic. The cross-linking agent may be used in combination with a water-soluble diamine. The polymer particles contain reactive hydroxyl groups and can be provided with spacer molecules to which biomolecules such as antibodies, peptides, proteins, enzymes, streptavidin, avidin, oligonucleotides, oligosaccharides or DNA can be coupled. Vinyl monomers having one or more functional groups such as carboxyl, hydroxyl, amino, aldehyde or oxirane may be grafted to the polymer particles by radical polymerization under the catalytic effect of cerium (IV).
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