Manufacturing and characterization of hydroxyapatite foams produced by gel-casting technique

The gel-casting technique has been implemented by several investigators, due to the fact that it presents a great potential to manufacture porous ceramic bodies with high mechanical resistance, complex geometries, and high dimensional precision. The hydroxyapatite (HA) is a ceramic that allows not also the bioactive fixation, but cells and nutrients invasion to promote the tissue regeneration; however, it presents low mechanical resistance. In this study, hydroxyapatite foams -using gel-casting with two different monomers and percent solids of 40 and 50%- were prepared. Obtained foams were characterized by X Ray-Diffraction (XRD), by Scanning Electron Microscope (SEM), by porosity and interconnectivity determination and by bioactivity assay. The results shown that the manufactured foams present open and interconnected porous with approximate size of 200 μm, porosity of 67%, and interconnectivity of 60%. The immersion tests in SBF confirmed the bioactivity of the hydroxyapatite, which demonstrates that this is a high potential process to manufacture porous bodies with useful characteristics in tissue engineering.