Three-dimensional printing of porous load-bearing bioceramic scaffolds

This article reports on the use of the binder jetting three-dimensional printing process combined with sintering to process bioceramic materials to form micro- and macroporous three-dimensional structures. Three different glass-ceramic formulations, apatite–wollastonite and two silicate-based glasses, have been processed using this route to create porous structures which have Young’s modulus equivalent to cortical bone and average bending strengths in the range 24–36 MPa. It is demonstrated that a range of macroporous geometries can be created with accuracies of ±0.25 mm over length scales up to 40 mm. Hot-stage microscopy is a valuable tool in the definition of processing parameters for the sintering step of the process. Overall, it is concluded that binder jetting followed by sintering offers a versatile process for the manufacture of load-bearing bioceramic components for bone replacement applications

Calcified Algae for Tissue Engineering.

This book presents the latest advances in marine structures and related biomaterials for applications in both soft- and hard-tissue engineering, as well as controlled drug delivery

Bioceramic granulates for use in 3D printing: Process engineering aspects

For the fabrication of patient individual bone replacement scaffolds using rapid prototyping (RP) technology, materials with properties adapted to the 3D printing process are needed. First of all the granulate properties of the building material have to match certain specifications concerning particle size and morphology. To fulfil these demands in laboratory scale a commercial fluidized bed granulator was modified to match the specific needs. The changes were tested spraying a sample granulate for the fabrication of synthetic bone grafts. This granulate could successfully be processed in the 3D printe

The morphology of anisotropic 3D-printed hydroxyapatite scaffolds

Three-dimensional (3D) scaffolds with tailored pores ranging from the nanometer to millimeter scale can support the reconstruction of centimeter-sized osseous defects. Three-dimensional-printing processes permit the voxel-wise fabrication of scaffolds. The present study rests upon 3D-printing with nanoporous hydroxyapatite granulates. The cylindrical design refers to a hollow bone with higher density at the periphery. The millimeter-wide central channel follows the symmetry axis and connects the perpendicularly arranged micro-pores. Synchrotron radiation-based micro computed tomography has served for the non-destructive characterization of the scaffolds. The 3D data treatments: is essential, since, for example, the two-dimensional distance maps overestimate the mean distances to the material by 33-50% with respect to the 3D analysis. The scaffolds contain 70% micrometer-wide pores that are interconnected. Using virtual spheres, which might be related to the cells migrating along the pores, the central channel remains accessible through the micro-pores for spheres with a diameter of up to (350 +/- 35) mu m. Registering the tomograms with their 3D-printing matrices has yielded the almost isotropic shrinking of (27 +/- 2)% owing to the sintering process. This registration also allows comparing the design and tomographic data in a quantitative manner to extract the quality of the fabricated scaffolds. Histological analysis of the scaffolds seeded with osteogenic-stimulated progenitor cells has confirmed the suitability of the 3D-printed scaffolds for potential clinical applications. (c) 2008 Elsevier Ltd. All rights reserve