Endogenous and exogenous ®broblast growth factor-2 modulate wound healing in the chick embryo chorioallantoic membrane

Re-epithelization and the formation of a granulation tissue consisting of in ̄ammatory cells, newly formed blood vessels, and ®broblasts embedded in a loose collagenous extracellular matrix, are critical events occurring during wound healing. In this study, utilizing the chick embryo chorioallantoic membrane (CAM) as an in vivo model of wound healing, we investigated the role of endogenous and exogenous ®broblast growth factor-2 (FGF-2) in the wound healing reparative processes. The results showed that: (1) neutralizing anti-FGF-2 antibodies (400 ng/ embryo) decreased signi®cantly the rate of wound healing (occurring only in 25% of specimens) when applied close to the edge of the wound, causing a signi®cant decrease of microvessel and ®broblast density, and of an in ̄ammatory macrophage in®ltrate in the wounded area; (2) conversely, the application of exogenous recombinant FGF-2 (1.0 lg/embryo) greatly accelerated the wound repair occurring approximately 24 h earlier than in untreated CAMs, stimulating angiogenesis, ®broblast proliferation, and macrophage in®ltration. These ®ndings demonstrate the role of FGF-2 in wound healing of the CAM and suggest that CAM, usually employed as an in vivo assay to study angiogenesis, can also be utilized as an in vivo model for the easy, rapid, and economic screening of molecules potentially able to a€ect the wound healing process.