Tackling current production of HAp and HAp-driven biomaterials

Hydroxyapatite (HAp)-based biomaterials are well-established for biomedical applications due to their extensive research work and clinical track record. Recent efforts have been focusing on the development of enhanced HAp systems, through combination with other materials, growth factors, and cells. However, manufacturing reproducible materials and process scalability are still major challenges. 3D printing emerged in the last decade as a technology that allows obtaining complex structures, using HAp as a core material or by incorporating it in other organic or inorganic matrices to obtain high resolution and on-demand production. While this approach has potential, there are limitations associated with the HAp characteristics (such as particle size distribution, size, crystallinity and morphology) used during printing that need to be overcome. In this context, manufacturing high volumes of HAp with uniform properties can be achieved using continuous production, which allows for the development of highly tailored materials that can be used for 3D-printing. This review discusses the latest trends in HAp production-derived performance materials. Moreover, it fills the gap in current papers by exploring the steps required for research-clinical-industry transitions.