Biodegradable heparin-loaded microspheres: carrier molecular composition and microsphere structure.
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]
Luo
Xianglin
X
State Key Laboratory of Polymer Materials and Engineering, College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 China. luoxl@mail.edu.cn
Qiu
Di
D
He
Bin
B
Wang
Lijian
L
Luo
Juan
J