Figure 8.

Proposed Mechanism of MAPC+DBM Scaffold bone healing. Data in this manuscript indicate high degrees of neovascularization and vessel maturity by 2 weeks. This increase in vasculature accelerates formation of the cartilage callus, which is then mineralized to form woven bone within the 2 week period. After 2 weeks, the increase in woven bone begins to plateau, and by 4 weeks there is increased lamellar bone and early marrow development. These results suggest that during the first 2 weeks of healing, defects in the DBM+MAPC scaffold treatment group progress through the callus formation and callus ossification stages, and at 4 weeks the woven bone is being resorbed and replaced with primary lamellar bone, which is characteristic of an advance into the bone remodeling state. Bone illustrations were adapted from Frohlich M (77).