Figure 3. Repair of critical-sized calvarial defects with Runx2 genetically engineered marrow stromal cells. MSCs were transduced with 300 pfu/cell of the indicated adenovirus. After 24 hrs, 5 x 10⁶ cells were seeded on a gelatin sponge and implanted into 5-mm calvarial defects as described in MATERIALS & METHODS. After 7 wks, implants were harvested and analyzed by x-ray (A), histology (B,C), and micro-CT (D). Panel C shows a higher magnification of the rectangular regions shown in B. Representative 3-D reconstruction images with micro-CT in each group are shown in panel D. Bars = (in panel B) 500 µm and (in panel C) 50 µm.