Impact of DAG stimulation on mineral synthesis, mineral structure and osteogenic differentiation of human cord blood stem cells

It remains unexplored in what way osteogenic stimulation with dexamethasone, ascorbic acid and beta-glycerol phosphate (DAG) influences the process of mineralization, the composition and structure of the assembled mineral. Therefore, we analyzed and characterized biomineralization in DAG-stimulated and unstimulated 3D human unrestricted somatic stem cell (USSC) cultures. Microspheres were analyzed by histological staining, scanning electron microscopy (SEM), semi-quantitative energy-dispersive X-ray spectroscopy (EDX), quantitative wavelength-dispersive X-ray spectroscopy (WDX), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and Raman spectroscopy. Mineral material was detected by SEM and histological staining in both groups, and showed structural differences. DAG influenced the differentiation of USSCs and the formation, structure and composition of the assembled mineral. SEM showed that cells of the +DAG spheres exhibited morphological signs of osteoblast-like cells. EDX and WDX confirmed a Ca-P mineral in both groups. Overall, the mineral material found showed structural similarities to the mineral substance of bony material. (C) 2011 Elsevier B.V. All rights reserved.