Bioceramics in Regenerative Medicine

Bones and hard tissues including the cartilage and teeth are of key importance for the human life, in terms of mobility, manipulation, chewing, and thus it is today one of the most demanding issues in medicine. In the last decades, a great deal of research effort has been devoted to the development of synthetic scaffolds, aiming to drive and sustain the bone regeneration process. Particularly relevant is the concept of "biomimetics", that is the intrinsic ability of a synthetic material to closely reproduce the chemical composition, physical properties, and architecture of native tissues, with the purpose to create 3-D environments able to deliver signals stimulating cell chemotaxis and specific differentiation of autologous stem cells. In the last decades, the research on regenerative bioceramics has greatly expanded, with the purpose to achieve the optimal composition, multi-scale structure, and mechanical performance. In this respect, the present article describes the main features requested for ceramic bone scaffolds and the most recent approaches to develop regenerative bioceramics, with particular respect to bioactive ceramic nanoparticles and their functionalization, 3-D porous ceramics and self-hardening injectable ceramic pastes and cements. Furthermore, the article explores recent advances in additive manufacturing techniques that, in spite of technological difficulties, are considered as a major approach to obtain implantable, personalized devices with organized and tailored porosity. Finally, the article gives an overview on some clinical results encouraging further research in the field.