Abstract
Obtaining 3-D inorganic devices with designed chemical composition, complex geometry, hierarchic structure and effective mechanical performance is a major scientific goal, still prevented by insurmountable technological limitations. With particular respect to the biomedical field, there is a lack in solutions ensuring the regeneration of long, load-bearing bone segments such as the ones of limbs, due to the still unmet goal of converging, in a unique device, bioactive chemical composition, multi-scale cell-conducive porosity and a hierarchically organized architecture capable of bearing and managing complex mechanical loads in a unique 3D implant. An emerging, but still very poorly explored approach in this respect, is given by biomorphic transformation processes, aimed at converting natural structures into functional 3D inorganic constructs with smart mechanical performance. Recent studies highlighted the use of heterogeneous gas-solid reactions as a valuable approach to obtain effective transformation of natural woods into hierarchically structured apatitic bone scaffolds. In this light, the present review illustrates critical aspects related to the application of such heterogeneous reactions when occurring in the 3D state, showing the relevance of a thorough kinetic control to achieve controlled phase transformations while maintaining the multi-scale architecture and the outstanding mechanical performance of the starting natural structure. These first results encourage the further investigation towards the biologic structures optimized by nature along the ages and then the development of biomorphic transformations as a radically new approach to enable a technological breakthrough in various research fields and opening to still unexplored industrial applications.
Highlights
Despite great progress in science and technology occurred in the past decades, to date insurmountable barriers still prevent the solution of crucial clinical needs, a substantial quantum leap in technological development is highly desired
In the attempt to overcome such limitations and obtain mechanically effective biomorphic scaffolds, suitable to fit critical size bone defects in load-bearing regions, we recently described the biomorphic transformation of rattan wood by using a multi-step process based on gas-solid reactions (Tampieri et al, 2019)
To face critical stages of the multi-step biomorphic transformation process involving gas-solid reactions, we found that the use of minimal energy conditions was relevant to control the kinetics of the different reactions involved in the transformation process and the diffusive phenomena that allowed the reactions to proceed from the surface to the bulk
Summary
Despite great progress in science and technology occurred in the past decades, to date insurmountable barriers still prevent the solution of crucial clinical needs, a substantial quantum leap in technological development is highly desired. To face critical stages of the multi-step biomorphic transformation process involving gas-solid reactions, we found that the use of minimal energy conditions was relevant to control the kinetics of the different reactions involved in the transformation process and the diffusive phenomena that allowed the reactions to proceed from the surface to the bulk Both these aspects are strongly inter-related with the compositional and microstructural evolution of the reacting solid, relevant when high specific surface and the maintenance of interconnected multi-scale porosity facilitate the mass transfer and the progress of the heterogeneous reactions. Further retained up to the final scaffold, such a porous nanostructure has invaluable utility in favouring the exchange of nutrients and autogenous growth factors when implanted in vivo, and improving the bio-resorption ability thanks to the higher specific surface area
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
