Precursors to Echogenic Polymer Microcapsules or Nanocapsules

Abstract

One aspect of the invention provides a precursor to an echogenic polymer microcapsule or nanocapsule. The precursor includes an emulsion including a polymer solution and an aqueous solution including a water-soluble sublimable solute. This aspect of the invention can have a variety of embodiments. In one embodiment, the water-soluble sublimable solute can be an ammonium salt. For example, the ammonium salt can be ammonium carbonate.

1 . A precursor to an echogenic polymer microcapsule or nanocapsule, the precursor comprising:
 an emulsion comprising:
 a polymer solution; and 
 an aqueous solution including a water-soluble sublimable solute. 
   
     
     
         2 . The precursor of  claim 1 , wherein the polymer solution includes a non-polar solvent. 
     
     
         3 . The precursor of  claim 1 , wherein the polymer solution includes a polymer selected from the group consisting of: a polyactide, a polyglycolide, a polycaprolactone, a copolymer of polylactide and polyglycolide, a copolymer of lactide and lactone, a polysaccharide, a polyanhydride, a polystyrene, a polyalkylcyanoacrylate, a polyamide, a polyphosphazene, a poly(methylmethacrylate), a polyurethane, a copolymer of methacrylic acid and acrylic acid, a copolymer of hydroxyethylmethacrylate and methylmethacrylate, a polyaminoacid, a polypeptide, and polylactic co-glycolic acid (PLGA). 
     
     
         4 . The precursor of  claim 1 , wherein the polymer is biocompatible. 
     
     
         5 . The precursor of  claim 1 , wherein the polymer is biodegradable. 
     
     
         6 . The precursor of  claim 1 , wherein the water-soluble sublimable solute is an ammonium salt. 
     
     
         7 . The precursor of  claim 6 , wherein the ammonium salt is ammonium carbonate. 
     
     
         8 . The precursor of  claim 1 , wherein the water-soluble sublimable solute is theobromine. 
     
     
         9 . The precursor of  claim 1 , wherein the water-soluble sublimable solute is theobromine acetate. 
     
     
         10 . The precursor of  claim 1 , wherein the emulsion is produced by sonication.