VEGF and angiogenesis
The principal driver of new blood vessel growth — and the first requirement of any thick construct.
Vascular endothelial growth factor (VEGF) is the dominant signal for angiogenesis, driving endothelial cells to proliferate, migrate, and organise into new vessels. Since the diffusion limit is the field's central bottleneck, VEGF is one of its most studied molecules.
Delivering it well is deceptively difficult. VEGF alone produces vessels that are leaky, disorganised, and unstable — they form and then regress. Stable vasculature requires a second phase in which mural cells are recruited to wrap and mature the vessel, which is where PDGF-BB enters; VEGF followed by PDGF works better than either alone, an explicitly sequential problem for Controlled release kinetics.
In bone the relationship is even tighter: vessel growth and bone formation are coupled, with endothelial cells and osteoblasts signalling to each other. That is why VEGF appears in bone growth-factor systems rather than being treated as a vascular concern alone.
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- SignalingPDGF in tissue repairPlatelet-derived growth factor — one of the earliest signals released at any wound.
- SignalingControlled release kineticsGetting the right signal to the right place at the right time — for the right duration.
- SignalingGrowth factor deliveryPotent, unstable, and short-lived — why delivering growth factors is harder than choosing them.
- SignalingTGF-β signalingThe superfamily containing the BMPs — and a signal whose effect depends entirely on context.
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