Towards cardiovascular stents fabricated by stereolithography

Abstract

Currently, cardiovascular diseases are the leading cause of death worldwide, and a global ageing population ensures increasing numbers for the foreseeable future. Atherosclerosis, responsible for 80\% of cardiovascular deaths, is nowadays treated with stents, which scaffold the balloon-dilated artery and seals the dissection flaps. In 2016, the Absorb GT1 (Abbott, USA) was approved by the FDA as the first bioresorbable stent (BRS), which further stimulated the research on degradable polymeric biomaterials. Polymeric BRS showed comparable characteristics as the most often used, drug-eluting stents (DES), with the added advantage of being fully biodegradable within two years. However, as several hurdles still need to be tackled, research to obtain the perfect BRS continues. A limited range of geometries and sizes influences the adaptation of the scaffold in a patient’s vessel, which subsequently affects the therapeutic outcome. Additive manufacturing (AM) could potentially be a method to produce cost-effective and patient-specific cardiovascular stents. This study aimed to contribute to innovations leading to the development of a next-generation stent. It presents novel information on Stereolithography (SLA) usability for the 3D printing of BRS and highlights the effects of structural and mechanical limitations, which are all inherent to the materials selection. Development and progress on specific capabilities have revealed and emphasized shortcomings in other domains. Fine-tuning the SLA printer settings and limitations, we were able to 3D print a 3 mm stent with promising morphological and mechanical characteristics. Future research and development should encompass all aspects of stent application, from manufacturing to deliverability, from functionality to solvability.