Patent ID: 8568786

Claim:
A method of making a filamentous polymeric nanocarrier that encapsulates a biologically active protein and protects it from proteolysis, the method comprising: (a) forming a primary emulsion using a freeze-thaw cycle of: (i) an amphiphilic diblock copolymer, which has a molecular weight of about 10,000 to about 100,000 Da and comprises a conjugate of a hydrophobic polymer block and a hydrophilic polymer block, wherein said amphiphilic diblock copolymer comprises greater than 81% to about 95% by weight of said hydrophobic polymer block; and (ii) a biologically active protein which is modified by attachment of polyethylene glycol; and (b) forming a secondary emulsion from said primary emulsion, and (c) recovering filamentous polymeric nanocarrier-encapsulated protein particles from said secondary emulsion, wherein said filamentous particles have a diameter of less than 70 nm and a length of from about 1 to about 50 microns, wherein said encapsulated protein is biologically active and protected from proteolysis.