| 摘要 |
Branched polyanhydrides that have superior pro- perties for use in the controlled delivery of substances, prepared by the polymerization of a dicarboxylic acid monomer and a branching agent. The branching agent is a polycarboxylic acid monomer such as 1,3,5-benzen- etricarboxylic acid ("BTC"), or an oligomerized fatty acid trimer. Alternatively, the branching agent is a poly- carboxylic acid polymer such as poly(acrylic acid) ("PAA"). These branched polymers have significantly higher molecular weights and lower specific viscosity than linear polymers prepared under similar conditions. A major advantage of branched polyanhydrides is that the degradation and release kinetics can be substantial- ly altered without significantly changing the physical properties of the polymer relative to the corresponding linear polymer. By manipulating both the diacid and the branching agent, a wide variety of biodegradable controlled delivery devices for diverse applications can be prepared.
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