| abstract |
The present invention relates to branched reactive water soluble polymers comprising two or more polymer branches, such as poly (ethylene glycol), linked via a heteroatom bond to a central aliphatic hydrocarbon core molecule. Branched polymers have at least one functional group for reacting with a biologically active agent to form a biologically active conjugate. The functional groups of the branched polymers are heteroatoms, -alkylene-, -O-alkylene-O-, -alkylene-O-alkylene-, -aryl-O-, -O-aryl-, (-O-alkyl It may be bonded directly to an aliphatic hydrocarbon core via an intermediary bond, such as a lene-) m or a (-alkylene-O-) m where m is from 1 to 10 bonds. |