Fig. 5

Histological examination of the ectopic bone with treatments of betulinic acid (25 or 50 μg), BMP2 (3 μg), and the combination of BetA and BMP2. All specimens used for radiographic analyses (Fig. 4) were formalin-fixed, paraffin-embedded and then cut into 7-μm-thick sections. The sections were then stained with hematoxylin and eosin. Low panels show the magnifying images of the box areas in upper panels. New bones are observed in BMP2- or BetA/BMP2-treated group as indicated with arrows. Microphotographs are shown at × 10 and × 100 magnification. n = 5