二氧化碳/环氧丙烷/γ-丁内酯三元共聚物微球降解性的研究

动物体内的体液和肠胃等器官的环境各不相同，这就要求各种不同用途的载药体的降解性能必须满足特定环境的要求。同时，可降解材料在不同的降解介质中通常有着不同的降解表现，这也决定着可降解材料的运用环境。因此，有必要对降解性材料在不同降解介质中的降解性进行专门的研究，由CO2和环氧化物合成的脂肪族聚碳酸酯具有良好的生物降解性能。

STUDY ON DEGRADABILITY OF MICROSPHERES MADE OF CARBON DIOXIDE/PROPYLENE OXIDE/γ-BUTYROLACTONE COPOLYMER

Some methods have been developed to use CO_2 as the raw material to produce degradable polymeric materials.The terpolymer of carbonate(PPGC) synthesized with the terpolymerization of CO_2,propylene oxide and γ-butyrolactone(GBL).GBL offered an ester structural unit making the copolymer easier to hydrolyze.Hence, PPCG should be of good degradability.In order to study its degradability,the polymer PPCG was used as materials for drag loading.The drug-loaded microspheres were obtained by the W/O/W type emulsions method. The microspheres were spherical in shape with smooth surfaces and good dispersion. The drug loading and encapsulation efficiency were 36.7% and 78.6%, respectively. The degradative behave was studied by SEM, XRD and drug release curves in different degradation medium were obtained.It was found that these microspheres could be degraded at faster speed in the basic media, while could not be degraded in the acidic media.The higher pH value of the medium was,the faster the initial degradative speed was.