아주대학교

초록/요약

One of the recent focuses of the pharmaceutical research is the development of biodegradable, reproducible, and well-defined drug delivery carriers. The critical point in the design of the drug delivery carriers is the understanding of the biodegradable mechanisms, because the drug release period can be varied from weeks to months, depending on the molecular weight and chemical composition of the biodegradable polymer segments. There are many types of synthetic aliphatic polyesters with good biodegradability and biocompatibility. Among several aliphatic polyesters, random block copolymers consisting of L-lactic acid (LLA), glycolic acid (GA) and ε-caprolactone (CL) have been recently prepared and examined as drug delivery carriers. The objects of this thesis are to make a candidate for drug delivery carrier for biomedical applications, using random triblock copolymers consisting of methoxy poly(ethylene glycol) (MPEG) and polyesters with different chemical compositions of the PLLA, PGA, and PCL. In chapter 2, MPEG-b-(PLLA-ran-PGA-ran-PCL) (MPEG-PLGC) block copolymers are prepared via ring-opening polymerization using MPEG as an initiator. The degradation and physical properties of MPEG-PLGC block copolymers are examined by varying both the ratio of the components and the copolymer composition of PLLA, PGA, and PCL, or by modifying their hydrophobicity and crystallinity. The degradation and physical properties of MPEG-PLGC block copolymers could be achieved by varying the amount of PLLA and PGA in the PCL segment. The chapter 3 are focused on practical application as drug delivery carrier of paclitaxel (Ptx), which is one of the most effective antineoplastic drugs discovered in recent decades. Ptx-loaded MPEG-PLGC block copolymers exhibit the controlled Ptx release profile. The work in this chapter shows that MPEG-PLGC block copolymers can act as drug depot with suitable degradation rate under physiological conditions. In conclusion, the present results confirm that MPEG-PLGC block copolymers can act as drug delivery carrier with biodegradation materials having an experimental window that is adjustable from a few weeks to a few months.