Development of 3D printable bioresorbable drug eluting coronary stents: An experimental and computational investigation

Over the last few years, the development of bioresorbable polymeric stents for the treatment of coronary artery diseases has attracted strong interest. In this study we introduced a computational modelling approach via a virtual testbed to investigate and predict the behaviour of 3D printed stents by applying inflation, hold and deflation sequences of loading. Bespoke designs – racetrack-cell and diamond-cell shaped stents were printed in a layer-by-layer manner using Fusion Deposition Modelling (FDM) where printable filaments comprised of bioresorbable polymers namely polydioxanone (PDO) and polylactic acid (PLA) blends at 60:40 and 70:30 ratios. The structural response of the stents was investigated by extracting from the numerical study the elastic recoil, foreshortening, longitudinal retraction, and dog-boning of the stents. Damage assessment indices were used to assess if a specific stent design failed during the deployment process and hence unsuitable for stent printing. The study revealed that racetrack designs are marginally better than the diamond stent designs. The study has shown the potential of computational modelling for the in-silico evaluation of 3D printed bioresorbable coronary artery stents.