两亲性嵌段共聚物聚乳酸-聚亮氨酸-聚乙二醇的合成及性能研究

Synthesis and study of amphiphilic poly(ethylene glycol)-poly(L-leucine)-poly(D,L-lactic acid)block copolymer

具有温度敏感的生物水凝胶因可根据温度变化发生相变而受到人们重视。采用直接熔融聚合法,先以外消旋乳酸(D,L-LA)和L-亮氨酸(Leu)为原料,辛酸亚锡为催化剂,合成了聚乳酸-聚亮氨酸;再以一定比例将上述两组分共聚物与一定分子量的聚乙二醇(PEG)混合,在辛酸亚锡为催化剂的情况下熔融聚合制备聚乳酸-聚亮氨酸-聚乙二醇三组分嵌段共聚物。采用傅里叶红外光谱(FTIR)、核磁共振波谱仪(1 H-NMR)和凝胶渗透色谱仪(GPC)对两组分和三组分共聚物进行了系统表征,所得三组分共聚物的一定浓度的水溶液在20～35℃时具有溶胶-凝胶转变特性,能够满足该生物友好材料在药物缓释领域中的应用。

Thermogelling polymers which undergo the sol-gel transition as the temperature increase have gained at- tention for their potential biomedical application, poly（L-leucine）-poly（D,L-lactic acid）was first prepared and then copoly- merized with poly（ethylene glycol）through melt polycondensation. This block copolymer was characterized by FTIR,1H- NMR and GPC. And the copolymer aqueous solution undergone the sol-gel transition as temperature increased from 25℃ to 30℃. This new material was very important with promising applications as long-term drug delivery carriers.