聚乳酸-b-聚（N~ε-苄氧羰基-L-赖氨酸）-b-聚乙二醇的合成与表征

SYNTHESIS AND CHARACTERIZATION OF AMPHIPHILIC TRIBLOCK COPOLYMERS PEG-POLY（N~ε-CBZ-LYSINE）-POLY（LACTIC ACID）

用端氨基聚乳酸做引发剂,在DMF中引发Nε-苄氧羰基-L-赖氨酸酐(Lys(Z)-NCA)聚合,合成了端氨基聚(Nε-苄氧羰基-L-赖氨酸)-b-聚乳酸两嵌段共聚物.以端羧基聚乙二醇经NHS活化与端氨基聚(Nε-苄氧羰基-L-赖氨酸)-b-聚乳酸偶联,合成了聚(乳酸-b-Nε-苄氧羰基-L-赖氨酸-b-乙二醇)三嵌段聚合物.利用IR、1H-NMR、GPC和TEM对它们的结构、形态进行了表征,结果表明,所合成的分子量可控、分子量分布窄(Mw/Mn=1.07)的嵌段共聚物,酰化反应产率达70%以上.同时聚乙二醇和Nε-苄氧羰基-L-赖氨酸被引入到聚乳酸主链中,在聚合物侧链脱保护后有望改善聚乳酸的细胞亲和性。

A poly（lactic acid）-based block copolymer was synthesized in order to increase the cell ahesion of poly（lactic acid）.Lys（Z）-NCA was first synthesized from Nε-carbobenzyloxy-L-lysine and triphosgene in THF.Diblock copolymers amino-ended poly（Nε-carbobonzyloxy-L-lysine）-b-poly（lactic acid） were synthesized in DMF in the condition that amino-ended PLA was used as initiator.Amphiphilic triblock copolymers poly（L-lactic acid）-b-poly（Nε-carbobonzyloxy-L-lysine）-b-poly（ethylene glycol） were synthesized in CHCl3 in the condition that amino-ended poly（lactic acid）-b-poly（Nε-carbobenzyloxy-L-lysine） was acylationed by carboxyl-terminal poly（ethylene glyco1）.The block copolymers were characterized via IR（infrared spectroscopy）,1H-NMR（nuclear magnetic resonance）,GPC（gel permeation chromatography） and TEM（transmission electron micrographs）.The results revealed that triblock copolymers with controlled Mn and narrow molecular weight distribution（Mw /Mn = 1.07） were synthesized,the acylation reaction yield was more than 70%.Poly（ethylene glyco1） and Nε-carbobenzyloxy-L-lysine were introduced into the main chain of poly（lactic acid）,and a kind of ideal bioabsorbable polymer materials were obtained.