Quantitative characterization of degradation processes in situ by means of a bioreactor coupled flow chamber under physiological conditions using time‐lapse SRµCT

• Published in: Materials and corrosion 2018-03, Vol.69 (3), p.298-306
• Main Authors: Zeller‐Plumhoff, Berit, Helmholz, Heike, Feyerabend, Frank, Dose, Thomas, Wilde, Fabian, Hipp, Alexander, Beckmann, Felix, Willumeit‐Römer, Regine, Hammel, Jörg U.
• Format: Article
• Language: English
• Subjects: Biocompatibility; Bioreactors; Computation; Computed tomography; corrosion; Corrosion cell; Degradation; Flow chambers; magnesium alloy; micro‐computed tomography; Surgical implants; Synchrotron radiation; Titanium
• ISSN: 0947-5117; 1521-4176
• DOI: 10.1002/maco.201709514

Magnesium and its alloys have in recent years emerged as a promising alternative to titanium‐based implants for medical applications due to favorable degradation properties and good biocompatibility. The degradation of materials is currently investigated by studying different samples of the same material at different time points after degradation in a medium. This study is presenting a high‐resolution time‐lapse investigation of Mg‐2Ag in culture medium using synchrotron radiation‐based micro‐computed tomography over the course of 5 days. The design of the custom‐built corrosion cell and bioreactor are described. The computed degradation rate after 5 days is in agreement with the literature. SRµCT enables the segmentation of cracks forming in the degradation layer due to stresses and hydrogen development. This work presents the design of a custom‐built flow cell manufactured for continuous tomographic imaging of corrosion processes. The setup includes a bioreactor with integrated environmental sensors and a pump for transport of the corrosion medium into the flow cell. The flow cell contains a heating stage to ensure constant temperature. A second sensor block can be added to monitor the outflowing medium.