聚(L-谷氨酸γ-苄酯)-聚四氢呋喃-聚(L-谷氨酸γ-苄酯)三嵌段共聚物的合成与表征

聚氨基酸是一类低毒性、生物相容性良好、易被机体吸收和代谢的可降解合成高分子材料，在药物控释载体、组织工程支架、生物材料表面改性方面得到了广泛应用．但其降解周期及降解速度通常难以控制，应用受到一定限制．通过共聚方法将生物相容和亲水性良好的聚乙二醇（PEG）引入聚氨基酸链段中形成两亲性嵌段共聚物旧，研究其自组装行为，及作为基因转染和药物控释载体等已成为高分子科学领域新的研究热点．

SYNTHESIS AND CHARACTERIZATION OF TRIBLOCK COPOLYMERS OF POLY(γ-BENZYL L-GLUTAMATE)-b-POLY(TETRAHYDROFURAN)-b-POLY(γ-BENZYL L-GLUTAMATE)

A kind of novel biodegradable triblock copolymers of(poly(γ-benzyl) Lglutamate)-b-poly(tetrahydrofuran)-b-poly(γ-benzyl L-glutamate) was synthesized by using amino-terminated poly(tetrahydrofuran) as a macroinitiator to initiate the anionic ring-opening polymerization of γ-benzyl Lglutamate N-carboxyanhydride(BLG-NCA) made from the reaction of γ-benzyl L-glutamate with triphosgen in tetrahydrofuran.The molecular structure was characterized by IR,()~1H-NMR,DSC and GPC measurements.The results showed that the triblock copolymers are well tailored by varying the feeding molar ratio of monomer to macroinitiator below 100.DSC analysis indicated that no crystalline phase is found in the copolymers and the glass transition temperature of each block gets close gradually with the block length of poly(γ-benzyl L-glutamate) growing.These triblock polymers could act as potential candidates for drug delivery carriers and tissue-engineered scaffolds.