22 research outputs found

    Defective proliferation and osteogenic potential with altered immunoregulatory phenotype of native bone marrow-multipotential stromal cells in atrophic fracture non-union

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    Bone marrow-Multipotential stromal cells (BM-MSCs) are increasingly used to treat complicated fracture healing e.g., non-union. Though, the quality of these autologous cells is not well characterized. We aimed to evaluate bone healing-related capacities of non-union BM-MSCs. Iliac crest-BM was aspirated from long-bone fracture patients with normal healing (U) or non-united (NU). Uncultured (native) CD271highCD45low cells or passage-zero cultured BM-MSCs were analyzed for gene expression levels, and functional assays were conducted using culture-expanded BM-MSCs. Blood samples were analyzed for serum cytokine levels. Uncultured NU-CD271highCD45low cells significantly expressed fewer transcripts of growth factor receptors, EGFR, FGFR1, and FGRF2 than U cells. Significant fewer transcripts of alkaline phosphatase (ALPL), osteocalcin (BGLAP), osteonectin (SPARC) and osteopontin (SPP1) were detected in NU-CD271highCD45low cells. Additionally, immunoregulation-related markers were differentially expressed between NU- and U-CD271highCD45low cells. Interestingly, passage-zero NU BM-MSCs showed low expression of immunosuppressive mediators. However, culture-expanded NU and U BM-MSCs exhibited comparable proliferation, osteogenesis, and immunosuppression. Serum cytokine levels were found similar for NU and U groups. Collectively, native NU-BM-MSCs seemed to have low proliferative and osteogenic capacities; therefore, enhancing their quality should be considered for regenerative therapies. Further research on distorted immunoregulatory molecules expression in BM-MSCs could potentially benefit the prediction of complicated fracture healing

    An investigation of the properties of large crystals of the zeolites dodecasil-3C and ferrierite by high-temperature birefringence microscopy and X-ray diffraction

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    Optical birefringence has been measured as a function of temperature for two types of siliceous zeolite crystals that contain organic template molecules. The specimens were prepared using modified solvothermal synthesis to produce large (similar to 1 mm dimension) crystals. In the case of the clathrasil dodecasil-3C the material undergoes a first-order phase transition at similar to 433 K that is reversible after heating to 873 K and cooling to room temperature. Comparison with powder X-ray diffraction data from a bulk sample shows that this is a ferroelastic tetragonal (I (4) over bar 2d) to cubic (Fd (3) over barm) transition, which is supported by the functional form of temperature variation of the birefringence. There is apparently no loss of the organic template involved in this transition. For the zeolite ferrierite, the plate-like crystals show a pronounced domain-like structure, which, although not due to twinning, shows a distinctive optical birefringence change on heating, suggesting that variable concentrations of organic template might be present in different domain-like regions. In this material there is no evidence for a change in crystal symmetry up to 873 K (Pnnm), despite apparent loss of some organic template from the material which, in turn, gives rise to strain birefringence at the edges parallel to the [010] direction
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