Camouflaging Endovascular Stents with an Endothelial Coat Using CD31 Domain 1-mimetic Peptides

Background Endovascular stents and flow diverters have become widely used for the treatment of vascular diseases; however, their effectiveness is often limited by the deposition and activation of blood platelets and leukocytes. The foreignness of these devices often triggers pathologic local reactions that impede their integration and compromise their efficacy. In this study, we developed a method to camouflage endovascular stents and flow diverters by coating them with a surface that mimics healthy endothelium, in order to promote more effective device integration and prevent the activation of blood cells. Methods We designed peptides using domain 1 and/or domain 2 of human CD31 and synthesized the chosen peptide to coat clinical-grade nitinol flow diverters and cobalt chromium balloon expandable stents. The coated stents were implanted in adult rabbits and included control groups of uncoated devices and drug-eluting CoCr stents. The rabbits were monitored for 60 days, during which we assessed the integration of the devices under a physiologic confluence of endothelial cells. Results Our results demonstrated that the stents coated with the CD31-Domain 1 mimicking peptide promoted a smooth integration of the devices under a physiologic confluence of endothelial cells. By day 7, the coated stents were entirely covered by a smooth endothelium, unlike bare-metal and drug-eluting stents which remained largely exposed to the flowing blood. By day 60, the coated stents demonstrated superiority over both bare-metal and drug-eluting stents, as they resulted in the formation of a “neo-arterial” wall at the entrance of the aneurysmal sac. Conclusion Our method provides a promising step towards the development of more effective and biocompatible endovascular devices. The CD31 domain 1 coating prevented the pathologic local reaction at the site of stent implantation and promoted faster and more effective device integration. Further studies are necessary to investigate the efficacy and safety of CD31 domain 1 coatings on a larger scale, as well as their long-term durability and potential clinical applications.