Despite the prevalent use of crystall
ine alloys
in current vascular stent
technology, new biomaterials are be
ing actively sought after to improve stent performance. In this study, we demonstrated the potential of a Zr–Al–Fe–Cu bulk metallic glass (BMG) to serve as a candidate stent material. The mechanical properties of the Zr-based BMG, determ
ined under both static and cyclic load
ings, were characterized by high strength, which would allow for the design of th
inner stent struts to improve stent biocompatibility. F
inite element
analysis further complemented the experimental results and revealed that a stent made of the Zr-based BMG was more compliant with the beats of a blood vessel, compared with medical 316L sta
inless steel. The Zr-based BMG was found to be corrosion resistant
in a simulated body environment, ow
ing to the presence of a highly stable ZrO
2-rich surface passive film.
Application-specific biocompatibility studies were conducted us
ing human aortic endothelial cells and smooth muscle cells. The Zr–Al–Fe–Cu BMG was found to support stronger adhesion and faster coverage of endothelial cells and slower growth of smooth muscle cells than 316L sta
inless steel. These results suggest that the Zr-based BMG could promote re-endothelialization and potentially lower the risk of restenosis, which are critical to improve vascular stent implantation
integration. In general, f
ind
ings
in this study raised the curta
in for the potential
application of BMGs as future candidates for stent
applications.
Statement of Significance
Vascular stents are medical devices typically used to restore the lumen of narrowed or clogged blood vessel. Despite the clinical success of metallic materials in stent-assisted angioplasty, post-surgery complications persist due to the mechanical failures, corrosion, and in-stent restenosis of current stents. To overcome these hurdles, strategies including new designs and surface functionalization have been exercised. In addition, the development of new materials with higher performance and biocompatibility can intrinsically reduce stent failure rates. The present study demonstrates the advantages of a novel material, named bulk metallic glass (BMG), over the benchmarked 316L stainless steel through experimental methods and computational simulations. It raises the curtain of new research endeavors on BMGs as competitive alternatives for stent applications.