Engineering Smarter Stents

An estimated two million people will need a coronary artery stent every year. A small mesh tube inserted into a narrow or blocked coronary artery, a stent can help ensure blood can continue to flow through the artery unimpeded. Today, many also contain a coating that releases a steady dose of medication to improve healing and keep the blockage from coming back.

Stents, however, are not without their risks: Restenosis—the re-narrowing of an artery—is one risk of coronary artery stents and occurs in three to 10 percent of cases in the first six to nine months. There is also a risk of blood clot formation, or thrombosis, that can also occur as the stent’s medicinal coating dissolves, exposing a metal surface.

McGowan Institute for Regenerative Medicine affiliated faculty member Youngjae Chun, PhD, Associate Professor of Industrial Engineering with a secondary appointment in the Department of Bioengineering at the University of Pittsburgh Swanson School of Engineering, is part of a consortium from industry, academia, and research that will seek to revolutionize the design of heart stents. The new stents will feature ultra-low-profile struts and a uniquely textured “smart” surface that will help improve healing and lessen the risks of restenosis and thrombosis.

The consortium, which includes members from industry, academia, and research, recently received $2 million in funding from the South Korean Ministry of Trade, Industry and Energy’s Outstanding Company Research Center Promotion Project (ATC+).

“The uniqueness of our stent is in both the thin struts that may reduce the risk of restenosis and the smart surface, which can help improve healing and prevent clots,” said Dr. Chun, who is a co-principal investigator. “When you introduce specialized micro and nanopatterns on the material—like grouped patterns, dimples, cavities, or diamond patterns—you can improve biocompatibility.”

Most widely used drug-eluting stents (DES) have a polymer coating mixed with a drug that is released over several months to help prevent restenosis. After that period, however, the metal stent is exposed. The unique, patterned surface on the proposed DES design would encourage endothelial cells—cells that form a barrier between vessels and tissue to control the flow of fluids in the body—to grow on the surface of the stent, helping to speed healing and reduce the risk of blood clot formation.

Dr. Chun’s lab will provide the computational modeling of the stent, as well as the creation of the smart surface. They will work with lead investigator and DES manufacturing company Osstem Cardiotech, as well as Daegu Gyeongbuk Medical Innovation Foundation, located in South Korea.

The project, “Development of a Coronary Artery Drug Eluting Stent That Contains Smart 60um Ultra-Thin Struts and Surface Structures for Rapid Vascular Healing Process,” began in April 2021 and will last four years.