Microdeformation of Three-Dimensional Cultured Fibroblasts Induces Gene Expression and Morphological Changes

Background: Vacuum-assisted closure induces microdeformations of the wound surface and accelerates healing of complex wounds; however, a thorough understanding of the biology of cellular mechanotransduction is lacking. We hypothesized that fibroblast shape and function can be altered in an in vitro vacuum-assisted closure device. Methods: A 3-dimensional fibrin matrix with cultured murine fibroblasts and an intervening polyurethane foam was exposed to 125 mm Hg suction and compared with similar wells without suction. We measured fibroblast proliferation and morphology using fluorescence microscopy and gene expression change using real-time reverse-transcriptase polymerase chain reaction at 24, 48, and 72 hours. Results: Wells exposed to suction induced significant proliferation of fibroblasts and morphologic changes visible by larger, rounder, and notable dendrite-like branching and process extensions. Type 1 collagen alpha 1 (COL1A1), fibroblast growth factor 2 (FGF2, bFGF), and transforming growth factor beta 1 (TGF beta 1) were all up-regulated after 48 hours of exposure to suction. Smooth muscle actin alpha 2 (Acta2, alpha-SMA) was up-regulated after 72 hours. Conclusions: Microdeformations produced by the combination of polyurethane foam and suction are associated with increased fibroblast proliferation and up-regulation of gene expressions in fibroblasts.