Fabrication and evaluation of the mechanical properties of reinforced biodegradable magnesium scaffolds using the space holder method

Introduction: Magnesium metallic biomaterials have drawn attention as a promising bone substitute material because they can degrade spontaneously and have mechanical properties similar to those of bone. Despite that, rapid degradation is a major disadvantage of magnesium. Therefore, different approaches such as reinforcing magnesium with other phases have been developed to overcome this problem. Objective: The aim of this study was to fabricate magnesium (Mg) scaffolds alloyed with zinc (Zn) and different concentrations of hydroxyapatite (HA) using powder metallurgy route, then porosity assessment, characterization and evaluation of the mechanical properties of these composites.Methods: Magnesium (Mg), zinc (Zn), hydroxyapatite (HA) and ammonium bicarbonate space holding agent powder particles were mixed. Mixtures were divided into 3 groups according to the hydroxyapatite percentage: Group A (Mg-4%Zn-0%HA), group B (Mg-4%Zn-5%HA) and group C (Mg-4%Zn-7.5%HA). To fabricate the scaffolds, powder metallurgy route was used. Porosity assessment and characterization using Scanning Electron Microscope (SEM) were done. Testing of mechanical properties was done. Results: Porosity assessment and SEM characterization showed that the scaffolds were highly porous with group B having the highest percentage of porosity. Mechanical testing showed that the specimens of group A had the highest strength and elastic modulus among all specimens and scaffolds of group C had higher values of strength and elastic modulus than group B.Conclusion: This work showed that fabrication of magnesium scaffolds alloyed with other elements using powder metallurgy route is feasible and the obtained scaffolds were found to be potential scaffold materials for bone tissue engineering.