Figure 2.

Key growth factors and events involved in the different phases of bone regeneration. The regeneration process can be divided into several phases that overlap each other. Each phase is regulated by many cytokines and growth factors secreted by different cell types. Revascularization and angiogenesis are ongoing through the inflammatory phase until the bone formation phase. BMP, bone morphogenetic protein; FGF, fibroblast growth factor; bFGF, basic FGF; IGF-1, insulin-like growth factor 1; MCP-1, monocyte chemoattractant protein 1; M-CSF, macrophage colony-stimulating factor; OPG, osteoprotegerin; PDGF, platelet-derived growth factor; PTH, parathyroid hormone; RANKL, receptor activator of nuclear factor κB ligand; SDF-1, stromal cell-derived factor 1; TGF-β, transforming growth factor β; TNF-α, tumor necrosis factor α; VEGF, vascular endothelial growth factor.