Heart disease is of great societal interest due to its drastic impact on health in industrialized nations, especially in developed countries where obesity rates are high and the typical diet is not conducive to cardiovascular health. While invasive procedures are not desirable, they are often crucial to ensuring patient survival. The five million coronary stents administered world- wide each year remain present in the human artery for the lifetime of the patient. This has resulted in the emergence of several serious side effects. A bioabsorbable metal stent that harmlessly erodes away over time could minimize the normal chronic risks associated with permanent stents. Our laboratory has been working to refine the composition and microstructure of biodegradable Zn-based binary alloys and test their behavior in the vascular environment over the last four years in an effort to develop a metal with mechanical properties and biocompatibility required for endovascular stent applications. Having contributed enormously to the scientific understanding of Zn-based systems, we are now ready to develop more complex Zn-based alloys with 2-3 alloying elements that meet benchmark values for biodegradable stents, including: 1) have superior corrosion fatigue resistance that eliminates early stage (6 to 9 months) fracturing of biodegradable stents (common problem in Mg-based and Zn-based stents prototyped in the last several years); 2) maintain in vivo corrosion rates close to the 0.02 mm/year value; 3) exhibit >200 MPa yield strength, and >25-30% elongation to failure; and 4) demonstrate biocompatibility in terms of short- and long-term inflammatory responses, re-endothelialization, and suppressed intimal hyperplasia, similar or better than 316L stainless steel (industrial standard for stent materials).

Public Health Relevance

Metal stents are commonly used to keep blood vessels open, but stents can cause long-term complications. Bioabsorbable metal stents that harmlessly erode away over time may minimize the normal chronic risks associated with permanent stents. A new zinc-based material for stents exhibiting enhanced corrosion fatigue resistance will be fabricated and optimized, and its biocompatibility and biodegradation behavior will be investigated using a rat model.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
1R01HL144739-01A1
Application #
9816239
Study Section
Biomaterials and Biointerfaces Study Section (BMBI)
Program Officer
Lee, Albert
Project Start
2019-06-15
Project End
2022-05-31
Budget Start
2019-06-15
Budget End
2020-05-31
Support Year
1
Fiscal Year
2019
Total Cost
Indirect Cost
Name
Michigan Technological University
Department
Administration
Type
Biomed Engr/Col Engr/Engr Sta
DUNS #
065453268
City
Houghton
State
MI
Country
United States
Zip Code
49931