Neovascularization is the natural formation of new blood vessels (neo- + vascular + -ization), usually in the form of functional microvascular networks, capable of perfusion by red blood cells, that form to serve as collateral circulation in response to local poor perfusion or ischemia.
Growth factors that inhibit neovascularization include those that affect endothelial cell division and differentiation.
Embryonic vasculogenesis occurs when endothelial cells precursors (hemangioblasts) begin to proliferate and migrate into avascular areas.
This primitive vascular system is necessary to provide adequate blood flow to cells, supplying oxygen and nutrients, and removing metabolic wastes.
The complex process is initiated in response to local tissue ischemia or hypoxia, leading to the release of angiogenic factors such as VEGF and HIF-1.
These blood vessels grow in abnormal ways and can invade into the vitreous humor, where they can hemorrhage or cause retinal detachment in neonates.
There is ongoing research exploring techniques that might be able to induce healthy neovascularization of ischemic cardiac tissues.