Fetal vs adult mesenchymal stem cells achieve greater gene expression, but less osteoinduction

Figure 7 Osteoinduction in vivo by mesenchymal stem cell-mediated bone morphogenic protein 2 delivery. Twelve 6-wk-old SCID mice received a 100 μL injection of 2 × 10⁶ MSCs or saline into the quadriceps muscles. Muscle samples harvested from the mice were examined by microradiography, 21 d after treatment. Treatment groups consisted of (A-B) saline control; C-D: Ad-BMP2-aMSC injection; E-F: plain aMSCs; G-H: Ad-BMP2-fMSCs; I-J: injected with plain fMSCs. The white arrows point at ossicles. The green arrow points at cortical thickening and new periosteal bone. BMP2: Bone morphogenic protein 2; Ad-GFP: E1-A-deleted-green fluorescent protein; fMSCs: Fetal mesenchymal stem cells; aMSCs: Adult mesenchymal stem cells.