FIG. 2.

Morphogenetic stages with major angiogenic regulatory growth factors and extracellular matrix molecules involved in neovascularization. Endothelial progenitors are differentiated from mesodermal cells as first step of vasculogenesis (a). EPCs differentiates into ECs (b). Organization of primitive vascular network are achieved by vacuole and lumen formation, branching and sprouting (c). Vessel is matured and stabilized by recruitment of SMC (d). Vessel destabilization occurs owing to SMC detachment (e). Nascent vessel sprouting occurs with the migration of endothelial cells up a growth factor gradient in response to biochemical growth factors (f). Vessel regression is observed during tissue repair and regeneration (g). Reprinted by permission from M. P. Lutolf and J. A. Hubbell, Nat. Biotechnol. 23(1), 47–55 (2005). Copyright 2005 Springer Nature Customer Service Center GmbH, Springer Nature.