Fig. 4

Regenerative potential of injected hES-MSCs varies based on GSH levels. A Macroscopic appearance of the defect lesions of the only-defect group and the treatment group which injected either naïve or GSH-low or -high hES-MSCs at 4, 8, and 12 weeks. B and C Safranin-O staining of the normal cartilage, only-defect and the treatment groups which injected either naïve or GSH-low or -high hES-MSCs at 4, 8, and 12 weeks (40 × , low magnification and 200 × , high magnification, respectively). D O’Driscoll scoring after injection (n = 8 per group). E (left) High-magnification image (200 × objective) to confirm collagen II expression using immunohistochemical staining and (right) quantification of collagen type II expression using scoring system (n = 8 per group). F Immunohistochemical staining of human-specific β2 microglobulin. ****p < 0.0001