Development of bioresorbable Mg-substituted tricalcium phosphate scaffolds for bone tissue engineering

Mg-substituted tricalcium phosphate (β-TCMP) samples were prepared either by the solid-state reaction of CaHPO4 (DCPA), CaCO3 and MgO powder at 1000 °C, or by a two-step process: wet precipitation of a precursor and further calcination of the precursor. The transition temperature from β-Tricalcium Phosphate (TCP) to α-TCP increases with the increase of Mg2+ content in β-TCMP samples. A β-TCMP sample with 3 mol% Mg2+ has a β-TCP to α-TCP transition temperature above 1300 °C, which was then used to fabricate various β-TCMP scaffolds in this study. Interconnected porous β-TCMP ceramics, with pore size > 100 μm and relative density of ~ 81% to 84%, were developed by a replication method using polyurethane foam as a template; micropores were also found in the scaffold struts. β-TCMP ceramics with a porous structure in the center and a dense shell-like structure outside, mimicking human bone, were fabricated by a molding method. Dense β-TCMP ceramic rings were also produced with an average compressive strength of 129 MPa.