title: In vitro and in vivo corrosion measurements of Mg-6Zn alloys in the bile.
abstract: Mg-6Zn alloy was studied as candidate biodegradable metallic implants for the common bile duct (CBD) in terms of its in vitro corrosion and in vivo corrosion. Electrochemical measurements, immersion tests and hydrogen evolution were performed in the bile and Hanks' solution to evaluate the in vitro degradation behavior of Mg-6Zn alloy. The results showed that the degradation rate and hydrogen evolution were higher when Mg-6Zn alloy immersed in the bile than in the Hanks' solution. The polarization resistance of the samples in the Hanks' solution was about 1.5 times to that in the bile. In the in vivo experiment, Mg-6Zn alloy stents were inserted in CBD of 42 rabbits, and CT scans, the value of total bilirubin (TB) and in vivo corrosion rate were determined. From the results of CT images and the fluctuations of TB values, it can be seen that the stent was degraded gradually in CBD. After 1 week post-implantation, the majority of the Mg-6Zn alloy sample remained in the CBD. Usually the required support time for CBD stent was approximately 7-10 days, thus the Mg-6Zn alloy stent was very close to the clinical requirement for CBD support materials. After three weeks, the residual weight of the Mg-6Zn alloy was only 9% of the original weight. The in vivo corrosion rate of Mg-6Zn alloy was ~0.107 mm·year(-1), which was much lower than that calculated in vitro (~0.72 mm·year(-1) by electrochemical test). Based on our research, there is promising for the Mg-6Zn alloy in CBD applications.
authors: Department of General Surgery, Nanjing Medical University Affiliated Wuxi No. 2 People's Hospital, Wuxi, Jiangsu 214002, PR China; Department of General Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, PR China.
authors: Yigang
authors: Y
authors: Chen
authors: Department of General Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, PR China.
authors: Jun
authors: J
authors: Yan
authors: Department of General Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, PR China.
authors: Zhigang
authors: Z
authors: Wang
authors: Department of General Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, PR China.
authors: Song
authors: S
authors: Yu
authors: Department of General Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, PR China.
authors: Xiaohu
authors: X
authors: Wang
authors: Department of General Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, PR China.
authors: Ziming
authors: Z
authors: Yuan
authors: State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China.
authors: Xiaonong
authors: X
authors: Zhang
authors: State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China. Electronic address: zcl@sjtu.edu.cn.
authors: Changli
authors: C
authors: Zhao
authors: Department of General Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, PR China. Electronic address: shanghaizhengqi@163.com.
authors: Qi
authors: Q
authors: Zheng
mesh_terms: D020341:Absorbable Implants; D000497:Alloys / Q000737:chemistry*; D000818:Animals; D001646:Bile / Q000737:chemistry* / Q000502:physiology; D001672:Biocompatible Materials / Q000737:chemistry; D003135:Common Bile Duct / Q000601:surgery; D003343:Corrosion; D025802:Electric Capacitance; D006801:Humans; D008274:Magnesium / Q000737:chemistry*; D008422:Materials Testing; D011817:Rabbits; D015607:Stents; D015032:Zinc / Q000737:chemistry*
chemical_list: D000497:Alloys; D001672:Biocompatible Materials; D008274:Magnesium; D015032:Zinc
keywords: Biodegradable stent; Common bile duct; Corrosion; Mg–Zn alloy