Human plasma fibronectin potentiates the mitogenic activity of platelet-derived growth factor and complements its wound healing effects

Integrin-mediated cell adhesion and growth factor stimuli are both required for optimal control of cell proliferation. In the context of skin injury, cell-derived fibronectin and platelet-derived growth factor play important roles in the stimulation of cell proliferation and migration, activities that are crucial to the healing process. To assess the ability of exogenously supplied plasma-derived fibronectin to stimulate wound repair and to study its ability to cooperate with platelet-derived growth factor-BB during healing, we devised a novel topical delivery formulation that allows the controlled release of both molecules to a wound. Using this topical formulation and the rabbit ear model of dermal wound healing, we show that plasma fibronectin is a potent stimulator of the wound healing process. We also show that administration of fibronectin and platelet-derived growth factor-BB in combination has additive wound healing effects. Finally, we report novel findings on the ability of soluble plasma fibronectin to potentiate the mitogenic effects of platelet-derived growth factor-BB in vitro. These findings not only show that optimal concentrations of exogenous fibronectin administered using an effective delivery system stimulate wound healing; they also suggest that PDGF-BB should be administered with fibronectin to achieve optimal therapeutic stimulation of wound healing.