Process

Abstract

A process for the preparation of coated polymer particles containing superparamagnetic crystals, said process comprising reacting surface-functionalized, superparamagnetic crystal-containing polymer particles of diameter less than 0.5 μm with at least one polyisocyanate and at least one diol.

1 . A process for the preparation of coated polymer particles containing superparamagnetic crystals, said process comprising reacting surface-functionalized, superparamagnetic crystal-containing polymer particles of diameter less than 0.5 μm with at least one polyisocyanate and at least one diol.  
     
     
         2 . A process as claimed in  claim 1  wherein at least two diols are employed.  
     
     
         3 . A process as claimed in  claim 1  wherein said diol is selected from the group consisting of polyethylene glycols and diols of formula HO((CH 2 ) m O) n H (where n is an integer of 1 to 15 and m is an integer of 2 to 6).  
     
     
         4 . A process as claimed in  claim 2  wherein said diols are diethyleneglycol and tetraethyleneglycol.  
     
     
         5 . A process as claimed in  claim 2  wherein one of said diols is polyethyleneglycol.  
     
     
         6 . A process as claimed in  claim 1  wherein said polyisocyanate is 4,4-methylene bis(phenylisocyanate) or a polyisocyanate comprising 4,4-methylene bis(phenylisocyanate) with CH 2 -phenylisocyanate residues (Desmodur™).  
     
     
         7 . A process as claimed in  claim 1  wherein said polyisocyanate is a diisocyanate.  
     
     
         8 . A process as claimed in  claim 1  wherein said particles are, in a first stage, reacted with a mixture of polyisocyanate and at least one diol in which the polyisocyanate is in a molar excess relative to the diol(s) and, in a second stage, subsequently reacted with at least one diol.  
     
     
         9 . A process as claimed in  claim 8  wherein two diols are used in the first stage of the reaction and one or two diols used in the second stage.  
     
     
         10 . A process as claimed in  claim 9  wherein diethyleneglycol and tetraethyleneglycol are used in both stages of the reaction.  
     
     
         11 . A process as claimed in  claim 1  wherein the particles are, in a first stage, reacted with polyisocyanate in the absence of diol, and, in a second stage, reacted with at least one diol.  
     
     
         12 . A process as claimed in  claim 11  wherein one dial is employed and said diol is a polyethylene glycol.  
     
     
         13 . A process as claimed in  claim 1  wherein the particles are amine functionalised.  
     
     
         14 . A process as claimed in  claim 1  wherein said surface-functionalized polymer particles are nitrated and reduced styrene-divinylbenzene polymer particles.  
     
     
         15 . A process as claimed in  claim 1  wherein the diameter of the polymer particles is between 150 and 250 nm.  
     
     
         16 . A process as claimed in  claim 1  in which said coated particle is subsequently tosylated.  
     
     
         17 . A process as claimed in  claim 1  wherein subsequent to the coating reaction, said particles are coupled to a drug molecule, reporter moiety or ligand.  
     
     
         18 . A process as claimed in  claim 17  wherein said ligand is a monoclonal antibody, polyclonal antibody, antibody fragment, nucleic acid, oligonucleotide, protein, oligopeptide, polysaccharide, sugar, peptide, peptide encoding nucleic acid molecule, antigen or drug.  
     
     
         19 . A process as claimed in  claim 18  wherein said ligand is streptavidin.  
     
     
         20 . A particle obtainable by the process of  claim 1 .  
     
     
         21 . A method of using the particle as claimed in  claim 20  in an assay.  
     
     
         22 . A method as claimed in  claim 21  wherein said assay is for the detection of nucleic acid or is an immunoassay.  
     
     
         23 . A method of using the particle as claimed in  claim 21  in hydrophobic interaction chromatography or reversed phase chromatography.