The effect of tissue expansion on dermal fibroblast contraction

Tissue expansion alters the function of skin cells. We studied the effects of expansion on the contractile function of dermal fibroblasts using an in vitro model, the fibroblast-populated collagen lattice (FPCL). Spherical expanders were placed dorsally in 30 Sprague-Dawley rats; one-half were serially inflated. One, 2, and 4 weeks later, 5 rats from each group were killed. Fibroblasts were cultured from dermis overlying the expanders and mixed with collagen, medium, and serum in petri dishes to form FPCL. Fibroblasts from 5 rats that had not undergone surgery were cultured to make control FPCL. Contraction was assessed by measuring the areas of the FPCL. At 48 hours, FPCL containing expanded fibroblasts had contracted significantly less than those containing unexpanded or control fibroblasts. Four weeks of expansion resulted in less contraction than 1 or 2 weeks. Tissue expansion inhibits the in vitro contractile function of dermal fibroblasts in the rat in a time-related fashion.