| 학회 | 한국고분자학회 |
| 학술대회 | 2005년 봄 (04/14 ~ 04/15, 전경련회관) |
| 권호 | 30권 1호, p.662 |
| 발표분야 | 의료용 고분자 부문위원회 |
| 제목 | pH-Responsive Micellization of Hydrotropic Block Copolymers: A New Approach for Drug Solubilization |
| 초록 | Recently, we defined a new concept of hydrotropic polymers, hydrogels, and micelles based on their ability to solubilize poorly water-soluble drugs by a unique mechanism normally accepted for low molecular weight hydrotropes[1,2]. Hydrotropic polymers containing the N-picolylnicotinamide (PNA) group, such as poly(2-(4-vinylbenzyloxy)-N-picolylnicotinamide) (P(2-VBOPNA)) and poly(6-(4-vinylbenzyloxy)-N-picolylnicotinamide) (P(6-VBOPNA)), were found to have pH-dependent water-solubility. They displayed solubilizing ability for paclitaxel only at the water-soluble state at pH ＜ 2.5, which made their application difficult in physiological pH. Thus, to develop a new delivery system possessing high solubility in a physiological condition is required to overcome the limitation of the hydrotropic polymers. In this work, we describe the synthesis of PEG-b-P(2-VBOPNA) and its pH-responsive micellization behavior in an aqueous media. The block copolymers were prepared by a two-step synthetic procedure. To prepare a macroinitiator (PEG-Br), MPEG was reacted with 2-bromopropionyl bromide, and PEG-b-P(2-VBOPNA)s were synthesized by atom transfer radical polymerization of 2-VBOPNA in the presence of PEG-Br. Dynamic light scattering and 1H NMR analysis showed that PEG-b-P(2-VBOPNA)s were freely-soluble at pH ＜ 2.5 but, upon pH increase above 2.5, they formed core-shell type polymer micelle structure. It can be suggested that PEG-b-P(2-VBOPNA) allows a unique drug loading method into polymer micelles, where the poorly soluble drugs are initially solubilized by the interaction with hydrotropic P(2-VBOPNA) block at low pH, and then drugs are possibly encapsulated into the micellar inner core upon pH-responsive micellization. References 1. S. C. Lee, G. Acharya, J. Lee, K. Park, Macromolecules, 36, 2248 (2003). 2. K. M. Huh, S. C. Lee, Y. W. Cho, J. Lee, J. H. Jeong, K. Park, J. Control. Rel., 101, 59 (2005). |
| 저자 | 이상천1, 김경자1, 박기남2 |
| 소속 | 1요업(세라믹)기술원, 2Purdue Univ. |
| 키워드 | Hydrotropic; Polymer Micelles; pH-Sensitive |
