两亲性嵌段共聚物聚苯丙氨酸-聚天冬氨酸的合成与表征

目的：以L-苯丙氨酸和L-天冬氨酸为原料，合成得到不同相对分子质量的聚苯丙氨酸-聚天冬氨酸两亲性氨基酸嵌段共聚物。方法以L-苯丙氨酸、L-天冬氨酸为原料，合成N-羧基-L-苯丙氨酸-环内酸酐、N-羧基-L-天冬氨酸苄酯-环内酸酐，采用开环聚合反应，得到目标化合物聚苯丙氨酸-聚天冬氨酸嵌段共聚物；利用芘荧光探针法对共聚物临界胶束浓度进行了测定。结果合成得到了疏水链段相对分子质量为500、2000、4000的两亲性嵌段共聚物，结构经氢核磁和红外光谱法确认；随着共聚物聚苯丙氨酸与聚天冬氨酸比例不同得到的聚合物的临界胶束浓度也发生了变化。结论疏水性链段聚苯丙氨酸链越长聚合物的临界胶束浓度越小。这为进一步研究不同性质的聚合物对药物纳米粒的稳定作用奠定了基础。

Synthesis and characterization of amphiphilic block copolymer of poly (L-phenylalanine)-b-poly(L-aspartic acid)

Objective To design and synthesize a different molecular mass block copolymer of poly(L-phenylalanine)-b-poly (L-aspartic acid)(PPA-PAA). Methods The L-phenylalanine and L-aspartic acid were used as raw materials to synthesize L-phenyl?alanine N-carboxy-ɑ-amino acid anhydride and L-aspartic acid-β-benzylester N-carboxy-ɑ-amino acid anhydride. The target com?pounds of amphiphilic block copolymer of PPA-PAA were synthesized by ring-opening polymerization. The critical micelle concentra?tion of the amphiphilic polymer was determined by pyrene fluorescence probe method. Results The copolymers of hydrophobic chain segment 500,2000,and 4000 were synthesized and the structures were confirmed by hydrogen nuclear magnetic resonance and Fouri?er transformed infrared. The critical micelle concentration of polymers changed with adjusting the feed ratio of PPA to PAA. Conclu?sion The results show that the longer the hydrophobic chain segment of PPA is,the smaller the critical micelle concentration of poly?mers. The results lay the groundwork for further studying the stabilizing effect of the drug polymer nanoparticles with different proper?ties.