Amniotic-Fluid Stem Cells: Growth Dynamics and Differentiation Potential after a CD-117-Based Selection Procedure
Figure 4
In vitro differentiation potential of AF cells into the osteogenic (ALP staining), adipogenic, and chondrogenic (Alcian blue staining) lineage. (a) while there was only a weak ALP staining in the CD117− cell fraction, (b) this was markedly stronger in the CD117+ cell population. (c) Unselected AF-cells also reveal a rather weak osteogenic differentiation as demonstrated by a weak ALP staining. (d) While no adipogenic differentiation as demonstrated by the Oil RedO staining could be observed in the CD117– cell fraction, (e) strong positive Oil Red O staining could be observed in the CD117+ fraction, (f) in the unselected population only a minor number of cells showed a Red Oil O positive staining. (g) After chondrogenic induction in CD 117 negative cells there is a diffuse Alcian blue staining detectable. (h) After chondrogenic induction the CD 117 positive cell fraction forms a firm pellet with a strong Alcian blue staining in the cortical zone. The pellets have a hyaline cartilage-like morphology based on characteristic lacunae formation containing round to oval shaped cells which resemble chondrocytes, which occur singly or in nests of two to three cells. (i) Diffuse Alcian blue staining can also be detected in unselected cells. (j) Densitometric analysis of Alcian blue staining in the different experimental groups There is a significant higher staining intensity in the CD117+ cell fraction compared to unselected or CD117− cells (). Scale bar in (a–i) = 100 μm, in the insets in (g–i) = 50 μm.
