Flow induced biodegradation behavior of magnesium metal: From bioreactors to in vivo models

Absorbable metals have been widely tested in various in vitro environments to evaluate their suitability as a vascular stent material. However, there exists a gap between in vivo and in vitro test results. A key step to solve this issue is to identify and test the relevant biochemical and biophysical microenvironments and parameters in test-systems. The purpose of this study was to develop a series of biomimetic flow bioreactors similar to in vivo/clinical conditions to reveal biodegradation behavior and mechanism of magnesium (Mg) metals or stents, such as in vitro varied fluid flow bioreactor with computational fluid dynamic calculation, in-situ or real-time electrochemical monitoring bioreactor, porcine aortal bioreactor as well as in vivo rat aortal system. Hydrodynamics as a biophysical vascular parameter directly affects on corrosion kinetics, types, rates and products. Establishing an appropriate methodology for accurate determinations of degradation parameters plays a vital part in predicting the fate of Mg-based stent.