Biodegradable Polymers

Biodegradable materials are now used in a wide range of therapeutic applications ranging from drug delivery to tissue engineering. The physical and mechanical properties of the materials play an important role in the determination of their potential use. The two main classes of synthetic biodegradable polymers are polyesters and polyanhydrides. To improve the biocompatibility and to achieve fine tuning of degradabilty of such materials, we have introduced natural compounds such as bile acids into such polymers. Research in this area focuses on the development of novel synthetic routes to degradable polymers based on bile acids. For the synthesis of polyanhydrides, polycondensation of novel bile acid dimers is being studied under both molten and dilute conditions. In the case of polyesters, we have chosen an emerging polymerization technique: entropy driven ring opening polymerisation. This technique requires macrocyclic monomers to be used and therefore allows large and rigid moieties to be incorporated in the polymer backbone. Moreover, the ring opening nature of this polymerisation makes it suitable for reaching high molecular weights without the use of large quantities of toxic coupling agents. These polymers are tested as drug carriers in the treatment of tumors and as bone tissue replacement materials.