In vitro and in vivo degradation behavior of Mg-2Sr-Ca and Mg-2Sr-Zn alloys

Kai Chen; Xinhui Xie; Hongyan Tang; Hui Sun; Ling Qin; Yufeng Zheng; Xuenan Gu; Yubo Fan

doi:10.1016/j.bioactmat.2020.02.014

In vitro and in vivo degradation behavior of Mg-2Sr-Ca and Mg-2Sr-Zn alloys

Bioact Mater. 2020 Feb 25;5(2):275-285. doi: 10.1016/j.bioactmat.2020.02.014. eCollection 2020 Jun.

Authors

Kai Chen^{1

2}, Xinhui Xie^{3

4}, Hongyan Tang^{1

2}, Hui Sun^{1

2}, Ling Qin⁴, Yufeng Zheng⁵, Xuenan Gu^{1

2}, Yubo Fan^{1

2

6}

Affiliations

¹ Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China.
² Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University, Beijing, 100083, China.
³ The Department of Orthopedics, ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, 210009, China.
⁴ Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong National Research Center for Rehabilitation Technical Aids, Beijing, 100176, China.
⁵ Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing, 100871, China.
⁶ National Research Center for Rehabilitation Technical Aids, Beijing, 100176, China.

Abstract

Magnesium alloys with integration of degradability and good mechanical performance are desired for orthopedic implants. In this paper, Mg-2Sr-Ca and Mg-2Sr-Zn alloys were prepared and the degradation as well as the bone response were investigated. Compared with the binary Mg-2Sr alloys, the addition of Ca and Zn improved the in vitro and in vivo corrosion resistance. Mg-2Sr-Ca and Mg-2Sr-Zn alloys exhibited more uniform corrosion and maintained the configuration of the implants 4 weeks post-implantation. The in vivo corrosion rates were 0.85 mm/yr for Mg-2Sr-Zn and 1.10 mm/yr for Mg-2Sr-Ca in comparison with 1.37 mm/yr for Mg-2Sr. The in vitro cell tests indicated that Mg-2Sr-Ca and Mg-2Sr-Zn alloys exhibited higher MG63 cell viability than Mg-2Sr alloy. Furthermore, these two alloys can promote the mineralization and new bone formation without inducing any significant adverse effects and this sound osteogenic properties suggest its attractive clinical potential.

Keywords: Biocompatibility; Degradation; In vivo test; Magnesium alloys; Orthopedic implants.