聚乙交酯丙交酯体内外生物降解性能的相关研究

通过对聚乙交酯丙交酯 (PGL A)进行体内和体外生物降解性的实验研究 ,探讨两种降解过程之间的关联性。体外实验是将 PGL A材料 (1cm× 1cm)分别浸泡在人工唾液和 PBS溶液中 ,体内 (动物 )试验是将材料直接植入 Wistar大白鼠的皮下组织 ,浸泡后或植入后 1～ 10周 ,每周计算材料的质量损耗率 ,每 2周进行分子量测定。实验结果显示 :PGL A材料在人工唾液中的降解要快于在 PBS液中的降解 ;材料质量损耗的发生慢于分子量的变化 ;体外的降解周期大约为 9～ 10周 ,体内降解周期为 8周左右 ,体内组的降解速率是体外组的 1.33倍。结论为PGL A体外降解主要是化学降解过程 ,通过酯键的水解来进行。体内降解过程中 ,应力环境和生物因素都会对材料的降解动力学产生影响 ,使降解过程明显加快 ,但体内和外降解都符合脂肪族聚酯降解的动力学模型 ,PGL A的体内外生物降解性之间存在一定的相关性。

Study on Relationship of Biodegradable Properties of PGLA Film in vivo and in vitro

This experimental study on the biodegradable properties of poly(glycolide-co-lactide)[PGLA] film in vivo and in vitro was aimed to investigate the relationship between in vivo degradation process and in vitro degradation process. First, PGLA film was cut to 1 cm x 1 cm in size. It was put into artificial saliva and PBS solution respectively in vitro, and was implanted into subcutaneous tissue in Wistar rat in vivo. Then the mass loss rate was calculated every week not only for sample in vitro but also in vivo. The molecular weight was measured every two weeks. The results showed that the degradable speed of PGLA was faster in artificial saliva than in PBS solution. The change of molecular weight was earlier than that of mass loss rate. The degradable period in vitro was about 9-10 weeks. The degradable period in vivo was about 8 weeks. The rate of in vivo degradation was 1.33 times faster than that of in vitro. In conclusion, the degradation of PGLA in vitro was mainly a chemical degradation process achieved by hydrolysis of ester bond. The degradation of PGLA in vivo would be affected by stress and by biological factors, thus the degradation process was apparently faster in vivo, but both accorded with the degradation kinetics model of aliphatic polyester. There was some relationship of biodegradation between in vitro and in vivo.