CONTROLLED CHEMISTRY FOR STUDYING COMBINED EFFECTS OF EXTRACELLULAR MATRIX PROTEINS
Antony K. Chen, Frank Delrio, Alexander Peterson, Koo-Hyun Chung, Kiran Bhadriraju and Anne L. Plant
The extracellular matrix (ECM) consists of a complex mixture of chemical and physical stimuli that play an important role in regulating cell behavior. The ability to elucidate physiological response with engineered ECM should facilitate our understanding of the role ECM plays in cellular function and disease evolution. Previously, we showed that thin films composed of fibrils of Type I collagen, the major protein comprising the ECM, induce reproducible and physiologically relevant cell behaviors. We have also shown that these films can be manipulated to adjust the mechanical properties of the fibrils, altering the response of cells as a result. Here, we report a novel ECM comprising both Type I collagen fibrils and fibronectin (FN), a prevalent ECM glycoprotein essential for cell adhesion, growth, migration and differentiation. FN adsorbs to the collagen fibrils with very high affinity, forming a combined ECM matrix. Binding of FN does not significantly alter the topography of collagen fibrils or the mechanical properties of the overall matrix. Fluorescent microscopy analysis indicates that A10 vascular smooth muscle cells respond to FN-treated collagen with increased spreading and proliferation. Antibody and peptide competitive assays suggest that the addition of FN alters integrin engagement to the matrix. Combined, these results indicate that the FN/Collagen combined ECM may serve as a useful platform for quantifying the relative contribution of different ECM factors to cell response.