Biodegradable Metals for Cardiovascular Stents: from Clinical Concerns to Recent Zn-Alloys.
Metallic stents are used to promote revascularization and maintain patency of plaqued or damaged arteries following balloon angioplasty. To mitigate the long-term side effects associated with corrosion-resistant stents (i.e., chronic inflammation and late stage thrombosis), a new generation of so-called "bioabsorbable" stents is currently being developed. The bioabsorbable coronary stents will corrode and be absorbed by the artery after completing their task as vascular scaffolding. Research spanning the last two decades has focused on biodegradable polymeric, iron-based, and magnesium-based stent materials. The inherent mechanical and surface properties of metals make them more attractive stent material candidates than their polymeric counterparts. A third class of metallic bioabsorbable materials that are based on zinc has been introduced in the last few years. This new zinc-based class of materials demonstrates the potential for an absorbable metallic stent with the mechanical and biodegradation characteristics required for optimal stent performance. This review compares bioabsorbable materials and summarizes progress towards bioabsorbable stents. It emphasizes the current understanding of physiological and biological benefits of zinc and its biocompatibility. Finally, the review provides an outlook on challenges in designing zinc-based stents of optimal mechanical properties and biodegradation rate.
Department of Materials Science and Engineering, Michigan Technological University, Houghton, MI, 49931.
Patrick K
PK
Bowen
Department of Biomedical Engineering, Michigan Technological University, Houghton, MI, 49931.
Emily R
ER
Shearier
Department of Materials Science and Engineering, Michigan Technological University, Houghton, MI, 49931.
Shan
S
Zhao
Department of Biomedical Engineering, Michigan Technological University, Houghton, MI, 49931.
Roger J
RJ
Guillory
Department of Biomedical Engineering, Michigan Technological University, Houghton, MI, 49931.
Feng
F
Zhao
Department of Biomedical Engineering, Michigan Technological University, Houghton, MI, 49931.
Jeremy
J
Goldman
Department of Materials Science and Engineering, Michigan Technological University, Houghton, MI, 49931.
Jaroslaw W
JW
Drelich
D020341:Absorbable Implants; D000497:Alloys / Q000627:therapeutic use*; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D003324:Coronary Artery Disease / Q000628:therapy*; D006801:Humans; D008670:Metals / Q000627:therapeutic use*; D015607:Stents; D015032:Zinc / Q000627:therapeutic use*
D000497:Alloys; D001672:Biocompatible Materials; D008670:Metals; D015032:Zinc
biodegradable stent; cardiovascular disease; endovascular stent; zinc