Microemulsions as precursors to solid nanoparticles

Abstract

The preparation of novel microemulsions to be used as precursors for solid nanoparticles is described. The microemulsion precursors consist of either alcohol-in-fluorocarbon microemulsions, liquid hydrocarbon-in-fluorocarbon microemulsions, or liquid hydrocarbon-in-water microemulsions. The formed solid nanoparticles have diameters below 200 nanometers and can be made to entrap various materials including drugs, magnets, and sensors. The solid nanoparticles can be made to target different cells in the body by the inclusion of a cell-specific targeting ligand. Methods of preparing the novel microemulsion precursors and methods to cure solid nanoparticles are provided.

1 - 21 . (canceled)  
     
     
         22 . The method according to  claim 34 , wherein said oil-in-water microemulsion comprises an oil phase comprised of at least one nanoparticle matrix material and at least one molecule of interest dispersed in an aqueous continuous phase to form a surfactant stabilized microemulsion between about 35° C. and about 100° C., wherein the microemulsion is cooled to room temperature while stirring to form solid stable nanoparticles containing at least one molecule of interest either entrapped in or adsorbed to the nanoparticles having a diameter of less than about 300 nanometers.  
     
     
         23 . The method according to  claim 22 , wherein the nanoparticle matrix material comprises one or more of the following materials: emulsifying wax, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene stearates, phospholipids, fatty acids or fatty alcohols or their derivatives, or combinations thereof.  
     
     
         24 . The method according to  claim 34 , wherein the liquid nanoparticle matrix material is present in the microemulsion at a concentration from about 0.1 to about 30 mg/mL.  
     
     
         25 . The method according to  claim 22 , wherein said oil phase is present as liquid droplets having a diameter of less than about 100 nanometers.  
     
     
         26 . The method according to  claim 22 , wherein said continuous phase is water or an aqueous buffer present at a concentration of greater than about 95% w/w.  
     
     
         27 . The method according to  claim 34 , wherein said surfactant or co-surfactant is polyoxyethylene alkyl ethers, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene stearates, hexadecyltrimethylammonium bromide, fatty alcohol and their derivatives, or combinations, thereof.  
     
     
         28 . The method according to  claim 34 , wherein said surfactant is present at a total concentration of about 1-5000 mM.  
     
     
         29 . The method according to  claim 34 , wherein said molecule of interest is present at a total concentration in the range of about 20 μg/mL to about 5 mg/mL.  
     
     
         30 . The method according to  claim 34 , wherein said molecule of interest is a drug molecule, a food, a magnet, or a sensor molecule.  
     
     
         31 . The method according to  claim 34 , wherein said molecule of interest comprises DNA.  
     
     
         32 . The method according to  claim 34 , wherein said molecule of interest is Gadolinium, its derivatives or complexes thereof.  
     
     
         33 . The method according to  claim 34 , wherein said nanoparticle is coated with a cell-specific ligand such as an antibody, carbohydrate, peptide, protein, or derivatives or combinations thereof.  
     
     
         34 . A method of making solid nanoparticles, comprising: 
 making an oil-in-water microemulsion by heating, the microemulsion comprising: 
 a liquid nanoparticle matrix material formed by heating a solid matrix material until melted;  
 a surfactant or a co-surfactant or a mixture thereof, and  
 a molecule of interest; and  
   forming the solid nanoparticles by directly cooling the microemulsion without aqueous dilution of from 1:10 to 1:100 (v/v), and where the molecule of interest is either entrapped in or adsorbed to the solid nanoparticles.