Fabrication of low-crystalline Mg-substituted β-tricalcium phosphate foam via dissolution–precipitation reaction

Abstract

Low-crystalline Mg-substituted β-tricalcium phosphate (Mg-β-TCP) block with a foaming structure (foam) was fabricated through a compositional conversion via a dissolution–precipitation reaction using α-tricalcium phosphate (α-TCP) foam as precursors in a solution containing 1.0 mol l⁻¹ MgCl₂ and 0.1 mol l⁻¹ NaH₂PO₄ under hydrothermal conditions at 100°C for 2 days. However, after immersion in the above-mentioned solution, the microstructure of the α-TCP foam consisted of polycrystalline aggregates, which are different from α-TCP foam and appear to have a typical sintered structure. The compressive strength and porosity of the Mg-β-TCP foam were 9.8 ± 1.02 MPa and 55.61 ± 4.13%, respectively. The fabricated Mg-β-TCP foam showed excellent interconnectivity. When the fabricated Mg-β-TCP foam was soaked in a dye solution, the inner structure of the fabricated Mg-β-TCP foam was completely stained. This suggests that the fabricated Mg-β-TCP foam might have excellent tissue penetration and good biocompatibility.