Die Fibrinmembran als Scaffold für ein rein autologes Bone Tissue Engineering

Autologous bone tissue engineering is aimung at the extracorporal rebuilding of lost bone using exclusively cells and matrix from the receiver organism which were manufactured, cultivated and combined in vitro. The aim of this study was to establish a autologous carrier matrix for cells and proteines consisting of fibrin and to characterize the properties of this 100% autologous construction in vitro and in vivo. Eight minipigs were used for manufacturing of the bone substitute using osteoblasts from the calvarian periosteum and endothelial cells from the jugular vein. Cells were cultivated until confluent stage and then seeded on a fibrin matrix based on autologous blood serum, combined with a autologous platelet-rich-plasma-concentrate and replantet in a critical size defect of the mandible. Specimens were taken at day 7 and 14 and analysed. Simultaneous attachment, proliferation, and differentiation of the cells on the carrier matrix was evaluated. In vitro results demonstrated complete attachment of the cells on the matrix surface after 6 hours and distinctive proliferation of both cell types after 48 hours without any apoptotic signs. In 6 of the 8 animals histomorphometric analyses revealed an accelerated bone regeneration. Immunohistologic staining for endothelial cells showed an increased angiogenic front within the fibrin matrix, which was clearly in front of the osteogenic front. With the help of cell tracking technique it was possible to identify the transplanted cells over the whole period of investigation. With this study we could demonstrate the possibility of creating a total autologous bone substitute. Based on vital transplanted cells and the nature of the matrix this construction is able to regenerate a bony defect in a fast and reliable manner. Keywords: Autologes Tissue Engineering, Fibrin, Endothelzellen, Osteoblasten, Autologous tissue engineering, fibrin, endothelial cells, osteoblasts