Mesenchymal stem cells (MSCs) have been repeatedly shown to be able to repair bone defects. The aim of this study was to characterize the osteog enic differentiation of miniature pig MSCs and markers of this differentiation in vitro . Flow-cytometrically characterized MSCs were seeded on cultivation plastic (collagen I and vitronectin coated/uncoated) or plasma clot (PC)/plasma- alginate clot (PAC) scaffolds and differentiated in osteogenic medium. During three weeks of differentiation, the formation of nodules and deposition of calcium were visualized by Alizarin Red Staining. In addition, the production of alkaline phosphatase (ALP) activity was quantitatively detected by fluorescence. The expression of osteopontin, osteonectin and osteocalcin were assayed by immunohistochemistry and Western Blot analysis. We revealed a decrease of osteopontin expression in 2D and 3D environment during differentiation. The weak initial osteonectin signal, culminating on 7th or 14th day of differentiation, depends on collagen I and vitronectin coating in 2D system. The highest activity of ALP was detected on 21th day of osteogenic differentiation. The PC scaffolds provided better conditions for osteogenic differentiation of MSCs than PAC scaffolds in vitro . We also observed expected effects of collagen I and vitronectin on the acceleration of osteogenic differentiation of miniature pig MSC. Our results indicate similar ability of miniature pig MSCs osteogenic differentiation in 2D and 3D environment, but the expression of osteogenic marker s in scaffolds and ECM coated monolayers started earlier than in the monolayers without ECM., J. Juhásová ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Computed tomography (CT) is an effective diagnostic modality for three-dimensional imaging of bone structures, including the geometry of their defects. The aim of the study was to create and optimize 3D geometrical and real plastic models of the distal femoral component of the knee with joint surface defects. Input data included CT images of stifle joints in twenty miniature pigs with iatrogenic osteochondrosis-like lesions in medial femoral condyle of the left knee. The animals were examined eight and sixteen weeks after surgery. Philips MX 8000 MX and View workstation were used for scanning parallel plane cross section slices and Cartesian discrete volume creation. On the average, 100 slices were performed in each stifle joint. Slice matrices size was 512 x 512 with slice thickness of 1 mm. Pixel (voxel) size in the slice plane was 0.5 mm (with average accuracy of ± 0.5 mm and typical volume size 512 × 512 × 100 voxels). Three-dimensional processing of CT data and 3D geometrical modelling, using interactive computer graphic system MediTools formerly developed here, consisted of tissue segmentation (raster based method combination and 5 % of manual correction), vectorization by the marching-cubes method, smoothing and decimation. Stifle- joint CT images of three individuals of different body size (small, medium and large) were selected to make the real plastic models of their distal femurs from plaster composite using rapid prototyping technology of Zcorporation. Accuracy of the modeling was ± 0.5 mm. The real plastic models of distal femurs can be used as a template for developing custom made press and fit scaffold implants seeded with mesenchymal stem cells that might be subsequently implanted into iatrogenic joint surface defects for articular cartilage-repair enhancement., P. Krupa, P. Kršek, M. Javorník, O. Dostál, R. Srnec, D. Usvald, P. Proks, H. Kecová, E. Amler, J. Jančář, P. Gál, L. Plánka, A. Nečas., and Obsahuje bibliografii