甲氧基聚乙二醇-<i>b</i>-聚<i>L</i>-半胱氨酸两亲性嵌段共聚物的合成与表征

甲氧基聚乙二醇-b-聚L-半胱氨酸两亲性嵌段共聚物的合成与表征

摘要: 首先以聚乙二醇单甲醚(mPEG-OH)为单体,采用经典的盖布瑞尔伯胺合成法合成了端氨基聚乙二醇单甲醚(mPEG-NH₂); 然后以mPEG-NH₂为引发剂,S-苄基L-半胱氨酸N-羧酸内酸酐(BCys-NCA)为原料,通过N-羧酸内酸酐(NCA)开环聚合反应和液氨/钠处理脱除侧链上的保护基团,合成了两亲性嵌段共聚物甲氧基聚乙二醇-b-聚L-半胱氨酸(mPEG-b-PCys)。采用傅里叶变换红外光谱、核磁共振氢谱对聚合物的结构和组成进行了表征。结果表明:成功制备了侧链具有还原性巯基的两亲性嵌段共聚物mPEG-b-PCys,并且其聚合度可控性良好。

Abstract: Amine-terminated mPEG (mPEG-NH₂) was first synthesized by Gabriel method using mPEG-OH as the monomer.Methoxy poly(ethylene glycol)-b-poly(L-cysteine) (mPEG-b-PCys) amphiphilic block copolymers were further synthesized by ring opening copolymerization of S-benzyl L-cysteine N-carboxyanhydride (BCys-NCA) initiated with the amine terminated mPEG and followed by the removal of the protected groups using liquid NH₃/Na.The structures of the polymers were characterized by Nuclear Magnetic Resonance spectroscopy (¹H-NMR) and Fourier Transform Infrared spectroscopy (FT-IR).Results showed that the amphiphilic block copolymers containing active thiol groups were synthesized successfully,and the degree of polymerization was controllable.