Proliferative Phase (Wound Healing)
The wound healing phase (days 3-21) where new tissue is actively formed. Fibroblasts produce collagen, new blood vessels grow (angiogenesis), and epithelial cells cover the wound surface. Growth factors including PDGF, FGF, and VEGF drive this phase.
Technical Context
Key proliferative phase events: fibroplasia (fibroblast migration into the wound along the fibrin scaffold, proliferation, and collagen synthesis — peak collagen deposition around day 7-14), angiogenesis (VEGF-driven sprouting of new capillaries from existing vessels, providing oxygen and nutrients to the healing tissue — the pink granulation tissue appearance reflects this rich capillary network), and re-epithelialisation (keratinocyte migration from wound edges and skin appendages, proliferation, and restoration of the epithelial barrier — growth factors EGF and KGF drive this process). The balance of matrix synthesis and degradation (MMPs vs TIMPs) determines wound quality. Growth factors including PDGF (FDA-approved as becaplermin gel for diabetic foot ulcers), FGF, EGF, and VEGF are the primary drivers. Research peptides targeting the proliferative phase typically aim to enhance fibroblast activity, collagen synthesis, or angiogenesis.