Kondo Shin-ichi, Yamamoto Keitarou, Sawama Yuka, Sasai Yasushi, Yamauchi Yukinori, Kuzuya Masayuki
Laboratory of Pharmaceutical Physical Chemistry, Gifu Pharmaceutical University, Japan.
Chem Pharm Bull (Tokyo). 2011;59(9):1200-2. doi: 10.1248/cpb.59.1200.
We fabricated novel pH-sensitive polymeric micelles consisting of amphiphilic block copolymer containing pyridyl groups as side chains in the hydrophobic block. The number average particle diameter of the polymeric micelles at pH 7 was approximately 200 nm. A decrease in pH resulted in deformation of the polymeric micelles over a very narrow pH range (between pH 5.7 and 5.6). Interestingly, micellization and demicellization occurred reversibly in this narrow pH range. Polymeric micelles incorporating 5-fluorouracil (5FU) were also prepared. Decreasing the pH of this polymeric micelle solution from 7 to 5.5 resulted in the rapid release of 5FU at pH 5.6; the drug was completely released within 30 min. These results suggest that deformation of the polymeric micelles caused the rapid release of 5FU.
我们制备了新型的pH敏感聚合物胶束，其由两亲性嵌段共聚物组成，该共聚物在疏水嵌段中含有吡啶基作为侧链。在pH 7时，聚合物胶束的数均粒径约为200 nm。pH降低导致聚合物胶束在非常窄的pH范围内（pH 5.7至5.6之间）发生变形。有趣的是，胶束化和去胶束化在这个窄pH范围内可逆地发生。还制备了包含5-氟尿嘧啶（5FU）的聚合物胶束。将该聚合物胶束溶液的pH从7降低到5.5导致在pH 5.6时5FU迅速释放；药物在30分钟内完全释放。这些结果表明聚合物胶束的变形导致了5FU的快速释放。
