A novel in vitro dermal wound-healing model incorporating a response to mechanical wounding and repopulation of a fibrin provisional matrix.

Previously our laboratory, and others, described an in vitro model for the study of fibroblast wound repopulation. The so-called punch-wounded, fibroblast-populated collagen lattice has been used extensively in tissue repair research. We now identify certain shortcomings with this model, which have led to its enhancement by the introduction of a provisional matrix fabricated in situ from fibrinogen and alpha-thrombin. In the previous model, fibroblasts repopulate the wound defect (WD) as a monolayer of cells and on reaching confluence, a process reminiscent of fibroplasia fills the wound space. The enhanced model, with fibrin acting as a provisional matrix, allowed fibroblasts to repopulate the WD as a three-dimensional network of cells that were morphologically different from cells migrating over the collagen substratum of the previous model. Fibroblast repopulation of the fibrin matrix was typically around double the rate of repopulation of the empty wound space. We propose this model as an enhanced, yet sufficiently reproducible, model for the study of fibroblast responses to tissue damage. It can be further enhanced by the addition of other cell types and matrix components.