Fig. 1.

Bone engineering protocol and timeline. Undifferentiated hESC were cultured in mesoderm-inducing medium for 1 wk. Adherent cells were expanded in monolayer for 4 passages (3–4 wk) and seeded on decellularized bone scaffolds in osteogenic medium for 3 d to allow cell attachment. Cell-seeded constructs were then cultured in osteogenic medium for 5 wk in either perfusion bioreactors or static dishes. Tissue development was evaluated after 3 and 5 wk of culture. Bioreactor-grown bone was implanted s.c. in SCID-beige mice for 8 wk to evaluate tissue stability and maturation.