title: Quantification of the repair process involved in the repair of a cell monolayer using an in vitro model of mechanical injury.
abstract: The processes of wound repair were investigated using an in vitro model of mechanical injury on confluent cell monolayers of either human umbilical vein endothelial cells (HUVEC), aortic endothelial (RAEC) or smooth muscle cells (VSMC) of the rat. A mechanical wounder was used to produce 11 parallel (400 microm wide) lesions across the monolayer and the movement of cells into the denuded area was quantified using image analysis. The lesioned area recovered completely in 72h, with proliferation occurring after 24h for endothelial cells and 18h for VSMC, as detected by an increase in cell numbers. The cell migration inhibitor Taxol (1ng/ml) abolished the increase in repair of HUVEC monolayers in the first 24h of repair, while actinomycin D had no effect before 24h but thereafter abolished the further repair which was associated with increased cell numbers. Repair of endothelial cells was accelerated by basic fibroblast growth factor (bFGF), vascular endothelial growth factor or platelet-derived growth factor-BB (PDGF), and in VSMC both bFGF and PDGF increased repair. This simple in vitro model of mechanical injury allows a quantitative study of the repair processes of a previously confluent monolayer and thus is a representation of mechanical damage in vivo.