Bioresorbable vascular metallic scaffolds: Current status and research trends

To combat the long-term side effects associated with present generation drug-eluting stents, provide opportunities for repeat scaffolding of plaqued arteries and treatment of coarctation of the aortas in infants and children, a new generation of bioresorbable stents has been introduced. Stents made of bioresorbable materials are corroded and absorbed by the body after completing their task as vascular scaffolding, allowing the stented arteries to restore their normal function. The concept is achieved by engineering stents that retain mechanical properties and integrity for at least 6 - 12 months before being broken down, metabolized, and harmlessly excreted by the body, leaving the treated vessel with a healthy endothelium, normal vasomotion and free of the implant. In this article, the authors briefly review the development status of bioresorbable materials for stenting applications, their mechanical properties and behavior in the vascular environment. Emphasis is given to new materials and under-explored research directions including long-term biocompatibility and emerging designs of bioactive stents. The goal for next generation bioresorbable metals is controlled release of therapeutic metal ions that could eliminate the need for anti-inflammatory drug eluting coatings, characteristic of current generation biostable stent metal scaffolds.