聚乳酸多孔支架的变温降解研究

DEGRADATION STUDY OF POLY(LACTIC ACID) POROUS SCAFFOLD AT DIFFERENT TEMPERATURES

考察了聚乳酸多孔支架不同温度下的降解行为,提出了一种降解速率的快速外推方法。以DL型丙交酯合成无定型聚乳酸,采用溶剂浇铸-粒子溶出的方法制备高孔隙率的多孔支架,考察了PBS缓冲液中、不同温度下聚乳酸多孔支架的降解行为,测定了特性黏数、质量损失和模量随时间的变化。根据聚乳酸多孔支架降解半衰期随温度的变化曲线,验证了分子量的变化满足A rrhen ius方程,计算得到降解的活化能,表明聚乳酸类材料的降解可以采用升温外推的方法来缩短降解实验时间。

This study is focused on tissue engineering porous scaffolds, especially the measurement of underlying degradation rates. In this paper, amorphous poly（lactic acid） was synthesized based on D,L-lactide, and porous scaffold was prepared by solvent-casting/particulate-leaching technique. It was confirmed that the degradation of a porous scaffold is much slower than the associated solid film. We measured viscosity, mass loss and modulus change of scaffolds during degradation in PBS at different temperatures. By examining the half-life of molecular weight under different temperatures, we confirmed that the biodegradation of PLA porous scaffolds obeys Arrhenius equation, and the activation energy has been calculated. Fast degradation at high tem- perature might be used to estimate degradation rate of associated scaffolds at the body temperature.