| 초록 |
The hydrophobic inner core surrounded by hydrophilic outer shell of amphiphilic block copolymer micelles can be used for drug carrier. The hydrophobic inner core serves as a reservior for hydrophobic drugs, whereas the hydrophilic outer shell stabilizes the micelles. In particular, biodegradable aliphatic polyesters combined with poly(ethylene glycol) have been used for this application. To investigate the architectural effect of block copolymer on critical micelle concentration (CMC), micelle size, drug loading efficiency (DLE), and drug release behavior, amphiphilic diblock and star-shaped block copolymers having poly(ethylene glycol) (PEG) as the hydrophilic outer shell and poly(ε-caprolactone) (PCL) as the hydrophobic inner core were prepared. Diblock copolymer was synthesized by ring opening polymerization (ROP) of ε-caprolactone in the presence of poly(ethylene glycol) methyl ether (MPEG). 3-arm star-shaped block copolymer was prepared by coupling diblock copolymer with 1,3,5-benzenetricarboxylic acid. 4-arm and 6-arm star-shaped block copolymers were prepared by coupling MPEG with 4-arm and 6-arm star-shaped PCL synthesized by ROP of ε-caprolactone in the presence of pentaerythritol and dipentaerythritol. The molecular weight and molecular weight distribution of these block copolymers were determined by GPC and 1H NMR analysis. Dynamic light scattering and fluorescence spectroscopic analysis were used to investigate the micellization behavior, drug loading efficiency, and drug release behavior of these block copolymers. |
