@misc{fierz_the_morphology_2008, 
author={Fierz, F.C., Beckmann, F., Huser, M., Irsen, S., Leukers, B., Witte, F., Degistirici, Oe., Andronache, A., Thie, M., Mueller, B.},
title={The morphology of anisotropic 3D-printed hydroxyapatite scaffolds},
year={2008},
howpublished = {journal article},
doi = {https://doi.org/10.1016/j.biomaterials.2008.06.012},
abstract = {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 nano-porous 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 treatment 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) μm. 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.},
note = {Online available at: \url{https://doi.org/10.1016/j.biomaterials.2008.06.012} (DOI). Fierz, F.; Beckmann, F.; Huser, M.; Irsen, S.; Leukers, B.; Witte, F.; Degistirici, O.; Andronache, A.; Thie, M.; Mueller, B.: The morphology of anisotropic 3D-printed hydroxyapatite scaffolds. Biomaterials. 2008. vol. 29, no. 28, 3799-3806. DOI: 10.1016/j.biomaterials.2008.06.012}}