Successful Low-Cost Scaffold-Free Cartilage Tissue Engineering Using Human Cartilage Progenitor Cell Spheroids Formed by Micromolded Nonadhesive Hydrogel

Figure 6

The CPC spheroids after spontaneous chondrogenesis are strongly positive for typical markers of cartilage tissue. (a) Hematoxylin and Eosin staining revealed rather rounded cells inside the spheroid. (b) N-cadherin is strongly present; (c–f) extracellular matrix typical markers of cartilage are shown throughout the spheroid area; (c) collagen type II; (d) collagen type VI; (e) aggrecan; (f) chondroitin sulfate. Bar size: 20 μm. (g) Control of nonspecific binding of secondary antibody (immune reaction carried out in the absence of the primary antibody). All reactions were done in the same moment. Bar size: 100 μm; μm: micrometers. (h) qPCR analysis of CPC spheroids showing upregulation of the SOX5 and SOX6 genes comparing to monolayer after 21 days of cell culture (). The expression of SOX9 gene was not statistically significant (). Standard errors are shown.

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