Abstract：
Poly(glycerol sebacate) (PGS) is an excellent scaffold material in tissue engineering due to good biocompatibility and tunable mechanical properties. The degradation properties of PGS have been primarily explored in static phosphate buffer solution or enzyme solution. It is vital to understand how the tensile stress affect the degradation rate. In this study, PGS was synthetized by melt polycondensation and its properties were characterized. Then an in vitro degradation device which could provide different constant tensile stresses was carefully designed and established, and the enzymatic degradation of PGS was tested under 0-150 kPa at 37°C. It was found that holes of PGS surface arranged almost parallel to each other and perpendicular to the direction of tensile stresses at 100 kPa and 150 kPa after 2-4 days degradation. After 8 days degradation, the ultimate tensile strength (UTS) of PGS at 150 kPa was 0.28 MPa and the elastic modulus was 1.11 MPa, while the UTS of PGS was 0.44 MPa and the elastic modulus was 1.63 MPa before degradation, both of them have significant differences. Hence, the tensile stress and degradation time were proportional to the appear time and size of holes, leading to the decrease of mass loss, UTS and elastic modulus. The relationship between stress and PGS degradation rates was quantitatively described through our degradation experiments, providing guidance for suitable PGS applications in the future.
摘要：
聚（癸二酸甘油酯）（PGS）由于具有良好的生物相容性和可调的机械性能，在组织工程中是一种出色的支架材料。PGS的降解特性已在静态磷酸盐缓冲溶液或酶溶液中进行了初步探索。了解拉伸应力如何影响降解速率至关重要。在这项研究中,采用熔融缩聚法合成了PGS，并对其性能进行了表征。然后精心设计并建立了可以提供不同恒定拉伸应力的体外降解装置，和PGS的酶降解在0-150kPa和37℃下测试。发现PGS表面的孔在2-4天降解后几乎彼此平行且垂直于100kPa和150kPa的拉伸应力方向。降解8天后，PGS在150kPa下的极限拉伸强度（UTS）为0.28MPa，弹性模量为1.11MPa，而PGS的UTS为0.44MPa，降解前的弹性模量为1.63MPa，两者有很大的不同。因此，拉伸应力和降解时间与孔的出现时间和大小成正比，导致质量损失的减少，UTS和弹性模量。通过我们的降解实验定量描述了应力和PGS降解率之间的关系，为未来合适的PGS应用提供指导。
