Unconventional, nature-inspired approaches to develop bioceramics for regenerative medicine

Materials science researchers and engineers are exploring the complex domain of biomaterials, as it requires consideration of biocompatibility and, in the frame of Regenerative Medicine, assessment on bioactivity, bio-reabsorbability and ability to be integrated and remodeled. Such a research field requires interdisciplinary approaches and robust knowledge of chemistry, biology and mechanics, in order to cope with the complex chemical composition, multiscale structure and biological functions of the organ to be replaced/regenerated. In fact, after decades of attempts to develop biomaterials able to effectively regenerate tissues/organs, most of them failed in their task and today the need of a radically new approach is commonly recognized. In this scenario, the article describes new frontiers in biomaterial development, fed by novel nature-inspired approaches, and able to circumvent the limitations of the current ceramic technology. Thus it will be illustrated how the biomineralization process, by which nature builds innumerable biologic structures, could be used to obtain scaffolds for regeneration of bone and also complex anatomical regions such as the osteochondral and periodontal tissues. Then the article will show recent developments for load-bearing scaffolds fabrication by using a revolutionary biomorphic transformation process, able to convert a natural hierarchically organized structure in fully ceramic and bioactive devices retaining the original 3-D multiscale structure and the unique damage tolerant performance. Finally, it will be shown how such new bio-devices can be powered by functionalization with magnetic doping and/or nanoparticles, to obtain on-demand activation of bio-functionalities. Particularly, the recent development of a biocompatible, bioactive superparamagnetic apatite is described, as a tool very promising to apply novel safer therapies in nanomedicine and to boost the endogenous potential of debilitated patients.