Material | Shape | Disinfection/sterilization | Animal | Implant site | Implant period month | Performance | Ref. |
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99.99% pure Zn | Wire, Φ0.25 mm × 15 mm | UV irradiation | SD rats | Abdominal aorta | 1.5, 3, 4.5, 6; 2.5, 4, 6.5 | At 2.5 months of implantation, neoendothelialization was completed. The neointima contains a thin layer of SMCs and an area of low-density inflammatory cells adjacent to the zinc metal layer and within the corrosion layer, with no signs of necrosis. Despite rapid corrosion after 4 months implantation, the thickness of the neointimal layer did not increase over time. Migration and matrix formation of nucleated cells in the corroded area were observed. No inflammatory response, local necrosis, and progressive intimal hyperplasia were observed | [75,76] | 99.99% pure Zn | Long wire, Φ0.25 mm | 70% ethanol disinfection | SD rats | Abdominal aorta | 1~12, 14, 20 | At 5, 6, and 8 months of implantation, there was higher cell density and chronic inflammation possibly related to stable corrosive activity. Chronic inflammation subsided between 10 and 20 months. No clear evidence of large-scale cytotoxicity was detected at any time point | [86] | 99.995% pure Zn | Stents, Φ3.0 mm × 10 mm, strut thickness: 165 μm | - | Japanese rabbits | Abdominal aorta | 1, 3, 6, 12 | No significant platelet adhesion or membranous thrombosis was observed after 3 d implantation. Neointimal coverage was observed at 1 month, indicating rapid endothelialization. No significant intimal hyperplasia or lumen loss was found at any time point, and no severe inflammation, platelet aggregation, or thrombosis was observed | [78] | Zn-0.1Li | Wire, Φ0.25 mm × 10 mm | - | SD rats | Abdominal aorta | 2, 4, 6.5, 9, 12 | At 11 months postimplantation, moderate chronic inflammation with non-obstructive neointima was still observed in the Zn-Li alloy group. Biocompatibility is slightly worse than pure Zn | [79] | | Material | Shape | Disinfection/ | Animal | Implant site | Implant | Performance | Ref. |
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| | sterilization | | | period | | | | | | | | month | | | Zn, Zn-xMg (x = 0.2, 0.5, 8) | Wire, 15 mm segment | Disinfection | SD rats | Abdominal aorta | 1.5, 3, 4.5, 6, 11 | Compared with pure Zn, the biocompatibility of Zn-xMg alloy showed a slight deterioration trend with the increase of Mg content. The inflammatory cell infiltration and neointima activation increased slightly. At 6 months, Zn-8Mg did not show significant intimal thickening, but exhibited moderate chronic inflammation and a reduction in the cross-sectional area of the lumen. At 11 months, inflammation had some resolution, but intimal thickening with discontinuous endothelial cells was appeared. It is speculated that Mg2Zn11 particles may induce deleterious macrophage responses thus disrupting the positive remodeling effect of Zn | [80] | Zn-xAl (x = 1, 3, 5) | Strip, 12 mm × 300 μm × 300 μm | 70% ethanol disinfection | SD rats | Abdominal aorta | 1.5, 3, 4.5, 6 | At 3 months of implantation, acute local inflammation with neutrophilic and eosinophilic infiltration was still observed. At 6 months, dense fibrotic deposits around the implant were observed, no necrotic tissue was detected. Zn-xAl had acceptable compatibility with surrounding arterial tissue | [81] | Zn-0.8Cu | Stent, Φ3.0 mm × 20 mm, wall thickness: ~127 μm | EO sterilization | White pigs | Coronary artery | 1, 3, 6, 9, 12, 18, 24 | Vascular endothelialization was completed within 1 months after stent implantation. ZnCu stent provided adequate structural support and exhibited an appropriate rate of degradation within 24 months, with no accumulation of degradation products, thrombosis or inflammatory responses | [84] | Zn-4Ag, Zn-4Ag-0.6Mn, Zn-4Ag- 0.8Cu-0.6Mn-0.15Zr | Wire, Φ0.25 mm × 15 mm | Disinfection | SD rats | Abdominal aorta | 3, 6 | At 6 months of implantation, a significant reduction of inflammatory activities was found in the quinary alloy relative to the other Zn-based materials. And inflammation, but not smooth muscle cell hyperplasia, is correlated with neointimal growth for the Zn-Ag-based alloys | [85] |
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