Fig. 5From: Induction of chondrogenesis of human placenta-derived mesenchymal stem cells via heparin-grafted human fibroblast derived matrixHistological analysis of subcutaneously implanted collagen spheroids at 4 weeks. a Safranin-O staining and b von Kossa staining. The boxed area appears in higher magnification. Scale bar is 500 and 200 μm, respectivelyBack to article page