Mechanical Characteristics, In Vitro Degradation, Cytotoxicity, and Antibacterial Evaluation of Zn-4.0Ag Alloy as a Biodegradable Material

Abstract

Zn-based biodegradable metallic materials have been regarded as new potential biomaterials for use as biodegradable implants, mainly because of the ideal degradation rate compared with those of Mg-based alloys and Fe-based alloys. In this study, we developed and investigated a novel Zn-4 wt % Ag alloy as a potential biodegradable metal. A thermomechanical treatment was applied to refine the microstructure and, consequently, to improve the mechanical properties, compared to pure Zn. The yield strength (YS), ultimate tensile strength (UTS) and elongation of the Zn-4Ag alloy are 157 MPa, 261 MPa, and 37%, respectively. The corrosion rate of Zn-4Ag calculated from released Zn ions in DMEM extracts is approximately 0.75 ± 0.16 μg cm–2 day–1, which is higher than that of pure Zn. In vitro cytotoxicity tests showed that the Zn-4Ag alloy exhibits acceptable toxicity to L929 and Saos-2 cells, and could effectively inhibit initial bacteria adhesion. This study shows that the Zn-4Ag exhibits excellent mechanical properties, predictable degradation behavior, acceptable biocompatibility, and effective antibacterial properties, which make it a candidate biodegradable material.

The influence of alloying and fabrication techniques on the mechanical properties, biodegradability and biocompatibility of zinc: A comprehensive review

“…Research on other binary combinations have also been reported, including zinc-copper (Zn-Cu) [66,106], zinc-lithium (Zn-Li) [107,108], zinc-aluminium (Zn-Al) [74,96,109], zinc-silver (Zn-Ag) [110,111], and zinc-manganese (Zn-Mn) [112,113].…”

“…Li et al [111], studying the cytocompatibility of Zn-4.0Ag with murine fibroblast cells (L929) and human primary osteosarcoma cell (Saos-2), noted that the addition of silver does not alter the biocompatibility of Zn. Moreover, Ag adds antibacterial qualities to biodegradable Zn against Streptococcus gordonii (S. gordonii).…”

Mechanical performance and biocompatibility assessment of Zn‐0.05wt%Mg‐(0.5, 1 wt%) Ag alloys

“…However, the alloys do not show obvious toxicity to the important organs of heart, liver, and kidney even though the Ag content may have negative effect on the biocompatibility. Since Zn‐4Ag alloy was examined to have certain cytotoxicity for the concentrated (100%, 33.3%) extracts to the cells (Li et al, 2018). The tracking of the biological reactions of the animals to the implanted alloys is more reliable.…”

“…Zn‐4Ag alloys degraded at the rate of 10.75 ± 0.16 μg cm −2 day −1 . The alloy showed cytotoxic effect with decreased viability and proliferation of L929 and Saos‐2 cells for the concentrated (100, 33.3%) extracts and non‐cytotoxic effect for the diluted (16.7, 10%) extracts of Zn‐4Ag alloys, respectively (Li et al, 2018).…”

“…Recently, we have manufactured Zn‐Mg‐Ag alloys with good strength and high antibacterial performance (Xiao et al, 2019). However, the biocompatibility of Ag including Zn alloys has rarely been reported (Li et al, 2018). Therefore, the compressive property, cytotoxicity and systemic toxicity of Zn‐0.05wt%Mg‐(0.5, 1 wt%)Ag were investigated in the present article.…”