Because the regeneration of large bone defects is limited by quantitative restrictions and risks of infections, the development of bioartificial bone substitutes is of great importance. To obtain a three-dimensional functional tissue-like graft, static cultivation is inexpedient due to limitations in cell density, nutrition and oxygen support. Dynamic cultivation in a bioreactor system can overcome these restrictions and furthermore provide the possibility to control the environment with regard to pH, oxygen content, and temperature. In this study, a three-dimensional bone construct was engineered by the use of dynamic bioreactor technology. Human adipose tissue derived mesenchymal stem cells were cultivated on a macroporous zirconium dioxide based ceramic disc called Sponceram. Furthermore, hydroxyapatite coated Sponceram was used. The cells were cultivated under dynamic conditions and compared with statically cultivated cells. The differentiation into osteoblasts was initiated by osteogenic supplements. Cellular proliferation during static and dynamic cultivation was compared measuring glucose and lactate concentration. The differentiation process was analysed determining AP-expression and using different specific staining methods. Our results demonstrate much higher proliferation rates during dynamic conditions in the bioreactor system compared to static cultivation measured by glucose consumption and lactate production. Cell densities on the scaffolds indicated higher proliferation on native Sponceram compared to hydroxyapatite coated Sponceram. With this study, we present an excellent method to enhance cellular proliferation and bone lineage specific growth of tissue like structures comprising fibrous (collagen) and globular (mineral) extracellular components.

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In this study, different collagen and ceramic based materials were characterized concerning their mechanical and biocompatible properties. Therefore, they were tested in static and dynamic cultivation using human mesenchymal stem cells derived from adipose tissue.Zirconia ) and a porous collagen-elastin-matrix (Matriderm J ) were similarly evaluated concerning their maximal tension and maximal deformation and compared with decellularized skin. The maximal deformations of the porous collagen materials were comparable but significantly increased compared to decellularized skin. The maximal tension of the porous matrices was five times lower than the maximal tension of decellularized skin.For the evaluation for cell culture applications, Sponceram In a rotating bed bioreactor system (Z J RP system, Zellwerk GmbH) the human mesenchymal stem cells were cultured under dynamic conditions on Sponceram J over a time period of 47 days using osteogenic differentiation medium. Continuous increasing glucose consumption and lactate production gives evidence of good cell proliferation. After cultivation, the Sponceram J discs were stained with von kossa and alizarin red which showed matrix calcification.In summary, the tested collagen-and ceramic materials are applicable for the cell culture applications whereas the ceramic materials are presenting a promising approach for bone tissue engineering implementations.

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