Strong Biomimetic Hydroxyapatite Scaffolds
Despite extensive efforts in the development of fabrication methods to prepare porous ceramic scaffolds for osseous tissue regeneration, all porous materials have a fundamental limitation- the inherent lack of strength associated with porosity. Shells (nacre), tooth and bone are frequently used as examples for how nature achieves strong and tough materials made out of weak components. So, the unresolved engineering dilemma is how to create a scaffold that is both porous and strong. The objective of this study was to mimic the architecture of natural materials in order to create a new generation of strong hydroxyapatite-based porous scaffolds. The porous inorganic scaffolds were fabricated by the controlled freezing of water-based hydroxyapatite (HA) slurries. The scaffolds obtained by this process have a lamellar architecture that exhibits similarities with the meso- and micro- structure of the inorganic component of nacre. Compressive strengths of 20 MPa were measured for lamellar scaffolds with densities of 32%, significantly better than for the HA with random porosity. In addition, the lamellar materials exhibit gradual fracture unlike conventional porous HA scaffolds. These biomimetic scaffolds could be the basis for a new generation of porous and composite biomaterials.
P. VINCENZINI and R. GIARDINO
S. Deville et al., "Strong Biomimetic Hydroxyapatite Scaffolds", Advances in Science and Technology, Vol. 49, pp. 148-152, 2006