Fibronectin does not enhance epidermal growth factor-mediated acceleration of corneal epithelial wound closure

Concomitant use of epidermal growth factor and fibronectin for the treatment of corneal epithelial wounds has a putative advantage of promoting complementary aspects of wound healing: epidermal growth factor enhances mitosis, while fibronectin increases cell-to-substrate adhesiveness and possibly cell motility. To determine if the combination of epidermal growth factor and fibronectin is synergistic in accelerating the speed of corneal epithelial wound coverage, epithelial wound closure rates were compared in serum-free rat corneal organ cultures among epidermal growth factor alone, fibronectin alone, their combination, and drug-free controls. Epidermal growth factor (50 to 1000 ng/mL) significantly increased the rate of wound closure over that of the drug-free controls, while fibronectin (50 to 100 micrograms/mL) had not significant effect. Wound closure rates with combined epidermal growth factor and fibronectin were no faster than with epidermal growth factor alone. The results indicate that fibronectin does not accelerate the rate of corneal epithelial migration when used alone or in combination with epidermal growth factor. This may reflect that the major role of fibronectin may be in the enhancement of cell-to-substrate adhesion and not of migration per se.