Fig 1.
Zn-3Ag alloy used for the production of a vascular stent.
Microphotographs of the grain size of Zn-3Ag alloy directly after casting (A) and extrusion (B). Zn-3Ag stent expandable to a diameter of 6 mm is shown (C).
Table 1.
Mechanical properties of Zn-3Ag alloy in comparison to bioresorbable (WE43, PLLA) and non-resorbable stent materials (CoCr, NiTi).
Fig 2.
Surface composition of Zn-3Ag.
Shown are XPS spectra of samples obtained after 60 s of sputtering of WE43 (black), Nitinol (red), Zn (green), Zn-3Ag (blue), and PLLA (cyan). For visibility curves were stacked by the following addition: Zn 500 cts/s, Zn-3Ag 1 000 cts/s, and NiTi 1 500 cts/s.
Fig 3.
Zn-3Ag biodegradation by simulated body fluid.
Zn concentration measured by atom absorption spectroscopy (AAS) after immersion of Zn-3Ag alloy samples in simulated body fluid (SBF) at the time of fluid change for 85 days were shown.
Fig 4.
Zn-3Ag affects proliferation of HAoSMCs.
Zn and Zn-3Ag reduce proliferation of human aortic smooth muscle cells (HAoSMC). Viable cells surrounding material discs (A), and cells attached directly to the material (B) stained with a green fluorescent cell proliferation (CSFE) kit and red fluorescent propidium-iodide were microphotographed and cell numbers calculated. Significance levels are illustrated as follows: *: p < .05; **: p < .01.
Fig 5.
Human blood hemolysis in contact with the stent materials Zn-3Ag, Nitinol, PLLA, and WE43 was measured in vitro. Shown are the results of 6 individual experiments.
Fig 6.
Comparable platelet adhesion on stent materials.
Platelet adhesion on Zn, Zn-3Ag, Nitinol, PLLA, and WE43 surfaces was measured and quantified in vitro. Quantified are three independent experiments. Significance levels are illustrated as follows: *: p < .05; **: p < .01.
Fig 7.
Zn-3Ag bioresorbable stents implanted in iliofemoral arteries of pigs.
Fluoroscopic X-ray images of Zn-3Ag bioresorbable vascular stent in porcine iliofemoral arteries immediately post-implantation (A), after 1 month (B), 3 months (C), and 6 months (D) show loss of radiopacity of the stents over time. Angiograms of Zn-3Ag stents reveal vessel patency without marked lumen narrowing or stent thrombosis post-implantation (E), after 1 month (F) after 3 months (G) and after 6 months (H).
Fig 8.
Zn-3Ag bioresorbable stents are rapidly covered by endothelium.
Histologic images of representative cross-sections of porcine iliofemoral arteries stented with a Zn-3Ag bioresorbable vascular stent after 1 month (A and D), 3 months (B and E), and 6 months (C and F). D, E, and F show magnified stent struts covered by neointima within the corresponding arterial cross-sections A, B, and C.