Process
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.