hfMSCs micromasses undergo chondrogenic differentiation.

<p>Expression of (A) glycosaminoglycans visualized by toluidine blue staining, nuclei are counterstained with haematoxylin, (B) collagen type II immunofluorescence, and (C) collagen type X immunohistochemistry (red-brown) during 5 weeks of chondrogenic differentiation of hfMSCs to chondrocytes. The top panel shows a magnification of the pellet cultures at week 1 and week 5 stained by toluidine blue demonstrating the change in cell morphology and the deposition of the extracellular matrix. The insets in panel B show higher magnifications of collagen type II positive chondrocytes.