Study on the synthesis of polyether grafted aliphatic polyesters and their application to drug delivery systems

Abstract

The goal of the research in this thesis is to synthesize novel amphiphilic biodegradable polymers for biomedical application and investigate their potential use as Drug Delivery Matrix. Biomedical polymer is material which has appropriate property as well as biocompatibility. Recently, due to the remarkable advance in medical field various branches of new area has been developed. Thus, development of new polymer materials for biomedical application is attracting much interest. Polymer material is advantageous in the sense of its ease of processing and its versatility in the structure. Among the various application fields in biomedical area, polymer plays major role especially in the drug delivery system. Properties of the polymer used in the drug delivery system affect on the release behavior as well as protection of the drug in the whole system. The polymers used in the drug delivery system can be divided into two big categories, that is biodegradable and non-biodegradable polymer. Biodegradable polymers degrade when it is applied to the human body and it is free from additional surgery to remove the material which has merit in patient compliance. Among the biodegradable polymers, aliphatic polyester is synthetic polymer which show excellent biocompatibility. Thus, many studies on the drug delivery system has dealt with aliphatic polyester and many studies are still on going. According to the previous studies, it is desirable to introduce hydrophilic moity, especially poly(ethylene glycol), to obtain amphiphilic property which shows improve in the drug delivery pattern and stability of the delivery matrix. This consideration motivated us to prepare novel graft structured amphiphilic biodegradable polymer by the ring opening polymerization and apply to the drug delivery system. In this work, polyethylene glycol grafted poly(L-lactide) (PLLA-g-PEG) (in Chapter II) and poly($\varepsilon$-caprolactone) (PCL-g-PEG) (in Chapter III) has prepared...