Abstract: The atherosclerosis is one of the most life-threatening diseases to modern people and percutaneous coronary intervention is an effective method for solving this disease. Currently, bare metal stent (BMS) has been widely used in the clinical practice. But two severe problems may be caused by BMS, i.e. stent thrombosis (ST) and in-stent restenosis (ISR). Bioabsorbable vascular stent (BVS) is one new general vascular stent that may solve the problems caused by BMS because of its good biocompatibility and biodegradability. In this study, the bioabsorbable vascular stents of different stent thickness, stent diameter and infill pattern made by poly(lactic acid) and cellulose nanocomposites were prepared respectively by a fused deposition modeling 3D printer. The in vitro experimental test for mechanical properties of the vascular stents were performed. Planar compression method for radial support property test and three-point bending method for flexibility of the stents were performed respectively. The test results indicate that in comparison to stents made by neat poly(lactic acid), the radial support property of modified composites stents with larger radius is increased by 47.6% and the flexibility is improved by 20.2% at most. The results of range analyses indicate that the stent thickness has the most significant impact on the in vitro mechanical properties and the infill pattern has less influence on the stent mechanical properties.

Key words: 3D printing, cellulose nanocomposites, vascular stent, poly(lactic acid), in vitro test for mechanical property