Patent ID: 8715739
Filing Date: 2014-05-06
Classification: A61K,B01J,B82Y,H01F

Abstract:
1. A method of preparing polymer coated microparticles, comprising: (a) providing starting nanoparticles having a hydrophobic surface and a particle diameter of between 1 and 100 nm, wherein the starting nanoparticles comprise at least one magnetic material; (b) suspending said starting nanoparticles in an hydrophobic solvent to provide a suspension of the particles; (c) mixing the suspension formed in step (b) and an aqueous phase in which the suspension is not miscible, thereby providing an emulsion of droplets of the suspension formed in step (b) dispersed in the aqueous phase, (c-1) thereafter sizing the emulsion formed in step (c) to provide an emulsion wherein the dispersed hydrophobic solvent droplets are sized between 2 and 20 μm; (d) evaporating enough hydrophobic solvent from the emulsion to assemble microparticles from the nanoparticles, wherein after the evaporation the microparticles become suspended in the aqueous phase; (e) providing a polymerizable monomer to the aqueous phase; and (f) polymerizing the polymerizable monomer to provide a polymer layer on the microparticles; wherein the polymer coated microparticles have a metal core that is greater than 50% of the mass of the mass of the polymer coated microparticles, wherein the metal core is the bare nanoparticles without both their hydrophobic coating and their polymer coating; and wherein the polymer coated microparticles have a size ranging from 0.01 to 10 μm.