3D Printing of Biodegradable Polymer Vascular Stents: A Review

Biodegradable polymer vascular stents (BPVSs) have been widely used in percutaneous coronary interventions for the treatment of coronary artery diseases. The development of BPVSs is an integrated process that combines material design/selection, manufacturing, and performance characterization. Three-dimensional (3D) printing technology is a powerful tool for polymer stent fabrication. Current review studies have focused primarily on the material and structural design of polymer stents but have failed to comprehensively discuss different 3D printing approaches and stent characterization techniques. In this paper, we address these shortcomings by discussing 3D printing methods and their application in BPVSs. First, some commonly used 3D printing methods (including material extrusion, vat polymerization, and powder bed fusion) and potential 3D printing strategies (including material jetting and binder jetting) for fabricating BPVSs are discussed; furthermore, the main post-treatments are summarized. Then, techniques to characterize the morphology, mechanical properties, and biological properties of the printed BPVSs are introduced. Subsequently, representative commercial BPVSs and lab-grade BPVSs are compared. Finally, based on the limitations of stent printing and characterization processes, future perspectives are proposed, which may help develop new techniques to fabricate more customized stents and accurately evaluate their performance.