| 학회 | 한국고분자학회 |
| 학술대회 | 2005년 봄 (04/14 ~ 04/15, 전경련회관) |
| 권호 | 30권 1호, p.28 |
| 발표분야 | 의료용 고분자 부문위원회 |
| 제목 | pH-Sensitive Hybrids Based on Complexation of Anionic Polymer Micelles and Poly(ethylene glycol) |
| 초록 | pH-Induced assembly systems have been widely explored in the area of drug delivery. For instance, the polymer-polymer complex hybrids formed by hydrogen bonding have been reported as pH-sensitive delivery systems of protein drugs such as insulin[1]. Although the hybrid based on pH-controlled complexation between polymers and colloids has become one of issues in the field of molecular assembly, its potential application as new drug carriers has not been suggested[2]. In this work, we describe a new pH-sensitive hybrid useful for site-specific oral drug delivery systems. The hybrid was formed by hydrogen-bonding-induced complexation between poly(ethylene glycol) (PEG) and anionic polymer micelles of poly(ε-caprolactone)-b-poly(methacrylic acid) (PCL-b-PMAA). PMAA constructing the micellar outer shell is known to undergo complexation with PEG via hydrogen bonding at an acidic pH. At pH 7.4, PEG and the polymer micelles existed separately since the carboxyl groups of PMAA were ionized and thus hydrogen bonding was not formed. The complexation began at pH 3.9 to produce the long-range interconnected micelle structure and further pH decrease resulted in the white precipitation of hybrids in water. This pH-dependent process was reversible and the initial micelle structure was restored by redispersion of the hybrids via pH increase. The complexed micelles in the solid hybrids was quantified by fluorescence intensity change of pyrene, labeled at the therminal of the PCL block. Below pH 3.7, about 100% micelles are complexed with PEG to form solid hybrids. The pH-sensitive complex hybrids possibly keep the activity of drugs during the transit of acid environment of the stomach. Furthermore, if the bioadhesion ability of the PMMA shell is enhanced by incorporating thiol groups or lectins, the oral bioavailability of drugs would be improved. References 1. I. C. Kwon, Y. H. Bae, S. W. Kim, Nature, 354, 291 (1991). 2. H. Mori, A. H. E. Muller, J. E. Klee, J. Am. Chem. Soc., 125, 3712 (2003). |
| 저자 | 이상천, 김경자 |
| 소속 | 요업(세라믹)기술원 |
| 키워드 | Polymer Micelles; pH-Responsive; Oral Drug Delivery |
