Regensburg 2007 – wissenschaftliches Programm

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SYBM: Symposium Bioinspired Materials

SYBM 1: Symposium Bioinspired Materials

SYBM 1.1: Hauptvortrag

Donnerstag, 29. März 2007, 09:30–10:00, H1

Using Ice to Mimic Nacre: From Structural Materials to Artificial Bone — •A. P. Tomsia, S. Deville, and E. Saiz — Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA

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 an ordered and homogeneous lamellar architecture that exhibits striking similarities with the meso- and micro- structure of the inorganic component of nacre. Compressive strengths of 20 to 60 MPa were measured for lamellar scaffolds with densities of 32 to 45%, 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.

Support is provided by the National Institute of Health under grant number NIH/NIDCR 1R01 DE11289 and 1 R01 DE015633-01