Biomimetic apatite coating on biomorphous alumina scaffolds

Highly porous Al₂O₃ scaffolds were prepared from natural cellulosic sponges via pyrolysis and Al-vapour phase infiltration. Subsequent oxidation and sintering in air resulted in porous Al₂O₃ ceramics with an open cellular morphology and a total porosity of 95%. The Al₂O₃-sponges were immersed in highly supersaturated simulated body fluid (5 × SBF) solutions with different Mg²⁺ and HCO³⁻ concentrations. After soaking of the porous Al₂O₃ sponges for 4 days a homogeneous calcium phosphate layer with a thickness of approximately 2 μm and a Ca : P ratio of 1.62 (apatite) was found.