The authors report on the manufacturing of mechanically stable β-tricalcium phosphate (β-TCP) structural hybrid scaffolds via the combination of additive manufacturing (CerAM VPP) and Freeze Foaming for engineering a potential bone replacement. In the first step, load bearing support structures were designed via FE simulation and 3D printed by CerAM VPP. In the second step, structures were foamed-in with a porous and degradable calcium phosphate (CaP) ceramic that mimics porous spongiosa. For this purpose, Fraunhofer IKTS used a process known as Freeze Foaming, which allows the foaming of any powdery material and the foaming-in into near-net-shape structures. Using a joint heat treatment, both structural components fused to form a structural hybrid. This bone construct had a 25-fold increased compressive strength compared to the pure CaP Freeze Foam and excellent biocompatibility with human osteoblastic MG-63 cells when compared to a bone grafting Curasan material for benchmark.

Osteoarthritis the quality and span of life in horses. Previous studies focused on nasal cartilage as a possible source for autologous chondrocyte implantation (ACI) in cartilage defects in humans. “HOX gene-negative” nasal chondrocytes adapted articular HOX patterns after implantation into caprine joint defects and produced cartilage matrix proteins. We compared the HOX gene profile of equine chondrocytes of nasal septum, anterior and posterior fetlock to identify nasal cartilage as a potential source for ACI in horses. Cartilage was harvested from seven horses after death and derived chondrocytes were cultured in a monolayer to fourth subcultivation. HOX A3, D1, D8 and chondrocyte markers COL2 and SOX9 were analyzed with qPCR in chondrocytes of three different locations obtained during passage 0 and passage 2. HOX gene expression showed no significant differences between the locations but varied significantly between the horses. HOX genes and SOX9 remained stable during culturing. Cultured nasal chondrocytes may be a target for future research in cell-based regenerative therapies in equine osteoarthritis. The involvement of HOX genes in the high regenerative and adaptive potential of nasal chondrocytes observed in previous studies could not be confirmed.