Two professors at Northwestern’s McCormick School of Engineering, Guillermo Ameer and Cheng Sun, have developed a method of 3D printing patient-specific vascular stents that are both flexible and biodegradable. These 3D printed stents can be pre-loaded with drugs that are released at site of implant, shortening the healing process in the walls of blood vessels. Meanwhile the unique polymer material allows the stent to exercise its mechanical function during the vessel’s initial dilation but slowly dissolve as the re-opened blood vessel recovers.

To meet the requirements of a perfect stent like induction of rapid endothelialization to restore the functions of vascular tissue and compliance with medical requirements, particularly the flexibility required to facilitate placement, researchers approached 3D Printing these Stents with PLA and PCL composites. Using Tubular 3D Printer, they 3D Printed the stents which were then seeded with cells and left for three days, and then tests were performed to assess the morphological features, cell proliferation, cell adhesion, degradation rate and radial behavior. Both PCL and PLA showed themselves to be biocompatible, and the composite stents showed the most promise, with medium levels of degradation rates and mechanical modulus.