Luo Xianglin, Qiu Di, He Bin, Wang Lijian, Luo Juan
State Key Laboratory of Polymer Materials and Engineering, College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 China.
Macromol Biosci. 2006 May 23;6(5):373-81. doi: 10.1002/mabi.200500236.
Microspheres of amphiphilic triblock polymers PLLA-PEG-PLLA were investigated as carriers for heparin delivery. Two series of PLLA-PEG-PLLA triblock were synthesized and prepared into microspheres with heparin loaded. The microspheres were hollow and the surface morphology varied from smooth to porous. The pore size increased with increasing PEG content. The microsphere size distribution showed that higher PEG content increased the average microsphere size. The release rate of heparin was closely related to the surface morphology of the microspheres. DSC spectra showed that both cold crystalline temperature (Tc) and crystalline melting temperature (Tm) of heparin-loaded microspheres were related to the copolymer composition and the Tc was lower than those of corresponding pure microspheres. [IMAGES: SEE TEXT]
两亲性三嵌段聚合物聚乳酸-聚乙二醇-聚乳酸（PLLA-PEG-PLLA）微球作为肝素递送载体进行了研究。合成了两个系列的PLLA-PEG-PLLA三嵌段聚合物，并制备了负载肝素的微球。微球为中空结构，表面形态从光滑到多孔不等。孔径随聚乙二醇含量的增加而增大。微球尺寸分布表明，较高的聚乙二醇含量增加了微球的平均尺寸。肝素的释放速率与微球的表面形态密切相关。差示扫描量热法（DSC）光谱表明，负载肝素的微球的冷结晶温度（Tc）和结晶熔融温度（Tm）均与共聚物组成有关，且Tc低于相应纯微球的Tc。[图像：见正文]
