What controls the antibacterial activity of Ti-Ag alloy, Ag ion or Ti2Ag particles?

Anqi Shi; Chenshun Zhu; Shan Fu; Renxian Wang; Gaowu Qin; Dafu Chen; Erlin Zhang

doi:10.1016/j.msec.2019.110548

What controls the antibacterial activity of Ti-Ag alloy, Ag ion or Ti₂Ag particles?

Mater Sci Eng C Mater Biol Appl. 2020 Apr:109:110548. doi: 10.1016/j.msec.2019.110548. Epub 2019 Dec 12.

Authors

Anqi Shi¹, Chenshun Zhu¹, Shan Fu¹, Renxian Wang², Gaowu Qin¹, Dafu Chen³, Erlin Zhang⁴

Affiliations

¹ Key Lab. for Anisotropy and Texture of Materials, Education Ministry of China, School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China; Research Center for Metallic Wires, Northeastern University, Shenyang 110819, China.
² Laboratory of Bone Tissue Engineering, Beijing Laboratory of Biomedical Materials, Beijing Research Institute of Orthopaedics and Traumatology, Beijing Jishuitan Hospital, Beijing 100035, China.
³ Laboratory of Bone Tissue Engineering, Beijing Laboratory of Biomedical Materials, Beijing Research Institute of Orthopaedics and Traumatology, Beijing Jishuitan Hospital, Beijing 100035, China. Electronic address: chendafu@jsthospital.org.
⁴ Key Lab. for Anisotropy and Texture of Materials, Education Ministry of China, School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China; Research Center for Metallic Wires, Northeastern University, Shenyang 110819, China. Electronic address: zhangel@atm.neu.edu.cn.

PMID: 32228943
DOI: 10.1016/j.msec.2019.110548

Abstract

Antibacterial metal materials, including Cu- and Ag-containing alloy, have attracted much attention worldwide. As for the antibacterial mechanism of the antibacterial alloys, there are two different views: metal ions sterilization and contact sterilization. For the purpose of revealing the key control factor, Titanium-silver (Ti-Ag) alloys with different silver contents were prepared and a surface acid etching was applied to change the silver ion release and the volume fraction of Ti₂Ag on the surface. The microstructure, phase composition, elemental composition, surface roughness, hydrophilicity, silver ion release and antibacterial properties of Ti-Ag alloys were studied comprehensively by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), contact angle and roughness test, silver ion dissolution test and antibacterial test. The results have shown that the increasing of Ag content did not bring about any change to the surface roughness and hydrophilicity but enhanced the Ag ion release while the surface acid etching improved the hydrophilicity, enhanced the Ag ion release and made more Ti₂Ag particles appear on the surface. The antibacterial experiments have shown that the antibacterial properties increased with the increasing of Ag content in Ti-Ag alloys and that the surface acid etching improved the antibacterial activity significantly. The calculated results and surface microstructure observation and XPS analysis demonstrated that the antibacterial activity of Ti-Ag alloys was mainly controlled by Ti₂Ag particle in a contact sterilization mode. Silver ion release from Ti-Ag alloy also contributed to antibacterial activity of Ti-Ag, but the Ag ion sterilization was not the key antibacterial mechanism. Finally, the CCK-8 results showed that all Ti-Ag alloys exhibited good cell compatibility.

Keywords: Antibacterial mechanism; Antibacterial property; Antibacterial titanium; Cytotoxicity; Surface acid etching; Ti-Ag alloy.

MeSH terms

Alloys* / chemistry
Alloys* / pharmacology
Animals
Biocompatible Materials* / chemistry
Biocompatible Materials* / metabolism
Cell Line
Materials Testing*
Mice
Silver* / chemistry
Silver* / pharmacology
Staphylococcus aureus / growth & development*
Titanium* / chemistry
Titanium* / pharmacology

Substances

Alloys
Biocompatible Materials
Silver
Titanium