生物相容性BAB型两亲嵌段共聚物的合成及其自组装

SYNTHESIS AND SELF-ASSEMBLING OF BIOCOMPATIBLE BAB AMPHIPHILIC TRIBLOCK COPOLYMERS POLY(N\+ε-CBZ-LYSINE)-PEG-POLY(N\+ε-CBZ-LYSINE)

两亲嵌段共聚物在选择性溶剂中的自组装行为已成为当前研究的一个热门课题.在一定的条件下,它会形成球形、棒状、管状、囊泡、洋葱等不同形态的聚集体[1～5],这些聚集体不仅能够作为模板构造纳米材料[6],而且由于这些形态本身具有纳米空腔结构,其包覆量要比实心的球形胶束大许多,在药物释放、物质包覆等方面有良好的应用前景[7].然而,要将两亲嵌段共聚物应用于生物体,除了要保证能够形成特定形态的聚集体外,还要求组成两亲嵌段共聚物的嵌段有良好的生物相容性和生物降解性.

Lys(z)-NCA was synthesized in the presence of triphosgene, amphiphilic triblock copolymers poly(N~ε-CBZ-Lysine)-PEG-poly(N~ε-CBZ-Lysine) were synthesized in DMF using amino-end ended PEG as initiator with the mechanism of anion ring opening polymerization. The structures of block copolymers were characterized by IR, ()~1H-NMR,GPC and DSC. The results showed triblock copolymers with expected structure and low polydispersity in molecular weight could be synthesized by this method. At the same time, the self-assembling behaviors of block copolymer were investigated by TEM.A novel helical aggregates were found to be formed in DMF. Because of biocompatibility of two components of block copolymers, these block copolymers have potential applications in the field of biomaterials.