Mesenchymal stem cells for tissue engineering of bone: 3D-cultivation and osteogenk differentiation on mineralized collagen

Aim: Due to their plasticity and high proliferation capacity in vitro, human mesenchymal stem cells (MSC) are promising candidates for substitution of mesenchymal tissues, such as bone. According to the tissue engineering concept, combinations of cells and three dimensional scaffolds are used to replace damaged tissue. Although various attempts have been made, the optimal combination of cells and artificial scaffold has not been found so far. Methods: In this work, human MSC were isolated from bone marrow aspirates according to standard protocols and cultivated on mineralized collagen. Osteogenic differentiation was induced by medium containing dexamethasone, ascorbic acid and beta-glycerophosphate. Cell proliferation on the scaffold (WST-1 vitality assay, total protein measurement) and osteogenic differentiation (quantitative Real-Time-RT-PCR) were monitored for 24 days. Results: Viable cells were found within the matrix throughout the cultivation period using histological and histochemical methods. Effective osteogenic differentiation could be demonstrated by the increase of expression of osteogenic marker genes (such as alkaline phosphatase) on a molecular level. Conclusion: Our results make the cell/matrix construct investigated in this work a promising candidate for tissue engineering of bone using mesenchymal stem cells. This has to be tested further by in vivo analysis.