Polymer coated microparticles

Abstract

Methods for preparing uniformly sized micropanicles, with an optional polymeric coating generally include:) providing nanoparticles, preferably having a size of betweennm andnm;) adding a hydrophobic surface layer to the nanoparticles;) making a suspension of the hydrophobic nanoparticles and a polymerization initiator in an hydrophobic solvent;) dissolving a monomer in the hydrophobic solvent;) making an emulsion by dispersing droplets of the hydrophobic solvent in a continuous aqueous phase with an emulsifier;) sizing the first emulsion to provide a second emulsion of the same components in which the droplets are substantially uniform and betweenandum in size;) evaporating at least a substantial portion of the dispersed hydrophobic droplets to assemble nanoparticles to form micropanicles suspended now in the aqueous phase;) replacing the first surfactant with a second surfactant, which is preferably a polymerizable surfactant;) adding a polymerizable monomer to the aqueous phase and allowing it to adsorb into the microparticle;) polymerizing the monomer(s) to provide a polymer layer on the micropanicles; and) functionalizing the polymer surface layer erf the micropanicles with one or more polymer, nanoparticle or biological macromolecular layers.