Exploring a Novel Bioabsorbable Zn–Ag–Mg Alloy Intended for Cardiovascular Applications

Abstract

Zn is considered as an excellent candidate material for endovascular applications due its outstanding combination of biodegradability and biofunctionality. In the present work, two novel Zn–Ag–Mg alloys with highly desirable mechanical, corrosion, and biological performance are introduced. Microstructural characterization revealed a significant grain refinement as a consequence of alloying (Ag, Mg) in conjunction with an adequate thermomechanical processing route for both alloy systems. Tensile test results indicated that the best mechanical properties in terms of yield strength (YS), ultimate tensile strength (UTS), and elongation to failure (% E) was achieved for the unidirectional rolled (UR) Zn–5.0Ag–0.5Mg alloy (A–1) with values of ~ 300 MPa, ~ 370 MPa, and ~ 40 %, respectively. However, a superior UTS was exhibited for the Zn–10.0Ag–1.0Mg alloy (A–2) with a value of ~ 450 MPa. The observed corrosion rate (CR) trend measured by potentiodynamic polarization test was: A–1 = 2.232 (mm/year) > A–2 = 1.405 (mm/year) > pure Zn = 0.935 (mm/year). When static immersion tests were performed, it was observed a different static corrosion rate (SCR) with the following trend: pure Zn = 0.14 (mm/year) > A–1 = 0.07 (mm/year) > A–2 = 0.05 (mm/year). Moreover, the indirect cell test showed that both alloys exhibited grade 0 of cytotoxicity at 10 % and 1 % of metal extracts. Finally, the proposed alloys showed excellent hemocompatibility characteristics compared to plastic and 316L SS control.