Fig. 6.

Histological evaluation of hiPSC-derived MSCs and chondrogenic cells implanted in rat knee joints. (a) H&E stain of chondrogenic differentiated hiPSC-derived MSCs shows persistent defect after transplantation of scaffold only and engraftment of cell implants with defect remodeling. (b) Alcian blue stain demonstrates no glycosaminoglycan (GAG) production of scaffold only, mildly positive GAG production of hiPSC-derived MSCs and markedly positive GAG production of chondrogenic cells. (c) Collagen II immunohistochemistry shows no production of Collagen type II in scaffold only and MSC transplants, but markedly positive Collagen type II production after transplantation of chondrogenic cells. (Arrow heads display the borders of the defect and the complete arrows show the residual of scaffold; scale bar is equal to 500 μm). (d) Human anti-nuclear specific immunofluorescent stain shows presence and long term viability of the human cells in the repaired tissue (Scale bar is equal to 50 μm)