Effect of dynamic and static loading during in vitro degradation of a braided composite bioresorbable cardiovascular stent

摘要

Bioresorbable cardiovascular stents are usually subjected to dynamic mechanical loads in vivo, which results in a different degradation profile compared to that measured under a static in vitro immersion test. In this study, a dynamic test platform was used to mimic cyclic pulsatile pressure and compared the changes in polymer properties of poly(p-dioxaone)/polycaprolane (PPDO/PCL) braided composite bioresorbable stents (BCBRSs) with static loading and non-loaded environments. The results showed static compressive load accelerated the changes in the hydrolysis process and crystallinity for polymers while the pulsatile pressure increased surface corrosion of the stent struts. Moreover, the degradation rate under dynamic loading was attenuated due to the mitigation of viscous flow of molecule chains and autocatalysis process, compared with that under static loading and non-loaded conditions. (C) 2019 Elsevier B.V. All rights reserved.