Nektar Therapeutics
BRANCHED POLYMERS

Abstract:

The present invention is directed to branched reactive water-soluble polymers comprising at least two polymer arms, such as poly(ethylene glycol), attached to a central aliphatic hydrocarbon core molecule through heteroatom linkages. The branched polymers bear at least one functional group for reacting with a biologically active agent to form a biologically active conjugate. The functional group of the branched polymer can be directly attached to the aliphatic hydrocarbon core or via an intervening linkage, such as a heteroatom, -alkylene-, --O-alkylene-O--, -alkylene-O-alkylene-, -aryl-O--, --O-aryl-, (--O-alkylene-).sub.m, or (-alkylene-O--).sub.m linkage, wherein m is 1-10.