Biodegradable magnesium implant: In vivo and in vitro convergence

In recent years, magnesium alloys have emerged as possible biodegradable implant material. A fundamental understanding of the nature of magnesium corrosion and the ability to control this process in vivo is critical to advancing the case for clinical use of magnesium based biomaterials. The biodegradation of magnesium is fundamentally linked to studies of its corrosion, which is dependent on the interfacing dynamics between the material and its environment. Thus, it is required to confirm what variable differentiate the corrosion behavior between in vitro and in vivo before optimizing and standardizing of in vitro test. This study was conducted to understand the biodegradation behavior of commercial AZ31 and Mg-Zn-Ca alloys with plasma electrolyte oxidation (PEO) under various biological environments using in vivo and in vitro testing methods mimicking in vivo physiological environment. This study is focused on the effect of Zn element concentration and PEO coating for magnesium alloys, and the correlation between the in vivo and in vitro in terms of corrosion rate, types of corrosion and corrosion product formation.