Fabrication and evaluation of print quality of Polylactic acid cylindrical scaffolds as stents and the effect of geometry on their shape memory properties

Memory-shaped polymers are thermally induced subsets of intelligent materials that require thermomechanical behavior to accurately understand their function. In this study, polymeric memory scaffolds were fabricated using polylactic acid by molten labeling method in three reticular honeycomb, rhombic and elliptical form. Parameters such as longitudinal dimensions and wall thickness of printed scaffolds compared to the designed scaffolds and solutions were presented to enhance the printing accuracy. Built-in scaffolds can be a good option for stent use. Formal memory properties experiments with 30% axial strain were performed to study the shape memory behavior of polymer on scaffolds. The results showed that the percentage of shape recovery in scaffolds with symmetric angular grid networks was higher than elliptical reticular stents. The minimum percentage of longitudinal recovery belonged to the elliptical reticular stent and was 74.5%. The percentage of longitudinal recovery of honeycomb and rhododendron reticular stents is approximately equal to 80.3%. The results of this study can be used to optimize the stent grid geometry to increase the retrieval force to resolving vascular clogging.