Investigation of porosity on mechanical properties, degradation and in-vitro cytotoxicity limit of Fe30Mn using space holder technique

Bioresorbable metallic implants are considered to be a new generation of transient fixation devices, which provide strong mechanical support during healing as well as effective integration with the host bone tissues, free of secondary surgery. We evaluated the microstructures and mechanical properties of iron-manganese alloys (Fe30Mn) with 0-, 5-, 10-, and 60-volume percent porosity, which was produced through ammonium bicarbonate (NH4HCO3) decomposition. We also investigated the influence of porosity concentration on the corrosion rate and cytotoxicity of the alloy. The average value of maximum compressive strength was 2-fold greater in the 0-vol% scaffolds than that in 60-vol% scaffolds. Scaffolds with 60-vol% porosity exhibited the highest average value of corrosion rate in a potentiodynamic polarization test among the four groups. However, the group influenced cellular viability negatively in a subsequent cytotoxicity test. Fe30Mn scaffolds with 10-vol% NH4HCO3 are considered promising resorbable scaffolds based on the results of compression tests, corrosion experiments and cytotoxicity studies.