A novel route for the synthesis of macroporous bioceramics for bone regeneration

A novel forming process based on direct foaming of ceramic suspensions was set up and optimized to produce highly porous hydroxyapatite (HA) scaffolds. A high-energy planetary ball milling was used to obtain stable foamed suspensions and to shorten the whole process, in comparison to previous approaches. The new process enabled the introduction of air bubbles in the ceramic suspension in tailored volume and size thus giving rise, upon sintering, to HA bodies with open and interconnected porosity associated with remarkable mechanical properties (e.g. a compressive strength σ =1 6.3 ± 4.3 MPa was exhibited by HA bodies with 65% pore volume). The reliability of the process in obtaining scaffolds was also assessed by the analysis of Weibull modulus. On this basis, this process can be considered as a novel promising route to develop macro-porous apatite scaffolds for regeneration of load-bearing bones, thus opening to new regenerative therapies for still unmet clinical needs.