Hydroxyapatite: From nanocrystals to hybrid nanocomposites for regenerative medicine

Scientific research on bone and osteochondral tissue regeneration is increasingly becoming the most promising response to a number of disabling pathologies with huge impact on the progressively growing and aging world population. The biomimicry of scaffolds with the target tissue is now universally considered to be a key requirement to properly instruct cells toward the restoration of specific physiological functioning. In this respect, this chapter presents an overview of recent findings on hydroxyapatite, biomimetic materials, and devices addressed to bone and osteochondral tissue regeneration. Particular focus is given to the novel biomimetic hydroxyapatite phases, including the newly discovered superparamagnetic hydroxyapatite nanoparticles and to the biomineralization process to develop bioinspired hybrid inorganic–polymeric porous scaffolds even endowed with magnetic features. Finally, the technology to transform ligneous sources into hierarchically organized biomorphic hydroxyapatite-based porous scaffolds that may provide novel and more effective solutions to assist the regeneration of long segmental bones was described.