| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a polymer useful as a drug delivery system with improved biocompatibility. <P>SOLUTION: The polymer may be made from a zwitterionic monomer having controlled structure and molecular weight, using living polymerization such as group or atom transfer radical polymerization. For instance, the polymer may be formed by atom transfer radical polymerization using a copper chloride catalyst, a ligand which is water soluble, and a water-soluble tertiary alkyl halide initiator to form a homopolymer having a controlled polydispersity of less than 1.5 and a block copolymer with other hydrophilic or hydrophobic monomers. One suitable zwitterionic monomer is 2-methacryloyloxy-2'-trimethylammoniumethyl phosphate inner salt. The block copolymer may spontaneously form micelles, and have zwitterionic, for instance phosphorylcholine, groups at the external surface. <P>COPYRIGHT: (C)2009,JPO&INPIT |
