| 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 reservoir 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 effect of molecular architecture of amphiphilic star-shaped block copolymers on critical micelle concentration (CMC), micelle size, drug loading efficiency (DLE), and drug release behavior, four and six-arm 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 synthesized through the divergent synthetic method. Four and six-arm star-shaped block copolymers were prepared by coupling MPEG with four and six-arm star-shaped PCL synthesized by ring opening polymerization (ROP) of ε-caprolactone in the presence of pentaerythritol and dipentaerythritol, respectively. The molecular weight and molecular weight distribution of polymers 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. As the arm number of star-shaped block copolymers increased, CMC and release rate decreased while the size of micelle and DLE increased. As hydrophobic chain length of star-shaped block copolymers increased, release rate decreased while the size of micelle, CMC, and DLE increased.
|
