Figure 3

The long-term survival of the implanted cells was confirmed by histological studies. Histological studies were performed at different time points, i.e., 4, 8, and 12 weeks (showed) after implantation, to directly test whether EGFP⁺ were persistently present in injury site. Typical images of newly regenerated bony callus in adjacent to the endogenous bone from different groups (top row, EGFP⁺ Ihh⁺ MSCs; middle row, EGFP⁺ MSCs; bottom row, control MSCs only) are shown. Note that many EGFP⁺ cells (either with or without Ihh overexpression) were not only survived but also apparently integrated into newly generated bone in both EGFP⁺ Ihh⁺ MSCs and EGFP⁺ MSCs groups. Overall, the first column is the phase images, the second column is the florescence images of GFP, and the third column is the merged images. Scale bars = 50 μm.