Eye-derived growth factor isolated from bovine retina and used for epidermal wound healing in vivo

Eye-derived growth factor (EDGF) has been found in several ocular tissues and shown to be able to stimulate the in vitro proliferation of cells from various tissues and organisms. It had already been shown that EDGF differs biochemically and biologically from other growth factors such as epidermal growth factor (EGF) and fibroblast growth factor in that it is the only one that can stimulate the in vitro growth of human adult keratinocytes. Moreover EDGF stimulates reepithelialization and neovascularization. In this paper we report data concerning the effect on the rate of epidermal wound healing in guinea pigs of different extracts obtained from adult bovine retina. Our results show that EDGF can significantly increase the rate of reepithelialization when epidermis is detached from dermis and removed after induction of a blister. The doses used were comparable to the ones used to obtain maximal increase of cell proliferation in vitro. However no attempt was made to further investigate the mechanism accounting for the observed wound healing. At 24 h, control wounds maintained under occlusive dressing had only about 50% of their surface covered with cells as opposed to EDGF-treated wounds which were covered up to about 80% (p = 0.05). On the other hand, EGF does not increase the rate of wound healing in this model even at 1000-fold higher doses than those used in in vitro bioassays. Although EDGF is still not purified to homogeneity and another 10- to 100-fold purification might be necessary to achieve homogeneity, our results suggest that EDGF may find therapeutic applications as a potent in vivo epidermal wound healing agent.