Patent ID: 8323632

Claim:
A method comprising: (i) covalently attaching a polypeptide segment having a terminus to a central core molecule selected from the group consisting of glycerol, a reducing sugar, pentaerythritol, hydroxypropyl-β-cyclodextrin, and a glycerol oligomer, and wherein the central core molecule bears a hydrophilic ethylene glycol oligomer chain having a molecular weight of about 100 Da to about 5,000 Da; and (ii) covalently attaching a hydrophilic polymer segment to the terminus of the polypeptide segment, wherein the hydrophilic polymer segment (a) is selected from the group consisting of poly(alkylene glycols), copolymers of ethylene glycol and propylene glycol, poly(olefinic alcohol), poly(vinylpyrrolidone), poly(hydroxyalkylmethacrylamide), poly(hydroxyalkylmethacrylate), poly(saccharides), poly(α-hydroxy acid), poly(vinyl alcohol), polyphosphazene, polyoxazoline and poly(N-acryloylmorpholine), (b) bears a capping group or a functional group selected from the group consisting of alkoxy, hydroxyl, active ester, active carbonate, acetal, aldehyde, aldehyde hydrate, alkyl or aryl sulfonate, halide, disulfide, alkenyl, acrylate, methacrylate, acrylamide, active sulfone, amine, hydrazide, thiol, carboxylic acid, isocyanate, isothiocyanate, maleimide, vinylsulfone, dithiopyridine, vinylpyridine, iodoacetamide, epoxide, glyoxal, dione, mesylate, tosylate and tresylate, to form a unimolecular multi-arm block copolymer having the structure: A(-O—B-L 1 -C) m′ -(L 2 -D-E) n′ wherein: A is a residue of the central core molecule; O is oxygen; B is the hydrophilic ethylene glycol oligomer chain; C is the polypeptide segment; D is the hydrophilic polymer segment; E is the capping group or functional group; L 1 is a linkage between B and C formed from a chemical reaction; L 2 is a linkage between C and D formed from a chemical reaction; (m′) is 3 to about 25; and (n′) is 2 to about 25, and (n′)≦(m′), wherein the unimolecular multi-arm block copolymer has a total molecular weight of about 10,000 Da to about 200,000 Da.