Fibronectin immobilized by a novel surface treatment regulates fibroblast attachment and spreading

In order to understand the influence of cell-adhesive molecules on anchorag e-dependent cell behavior on biomaterial surfaces, a model system is requir ed where these molecules can be applied to surfaces with controlled surface ligand density and resistance to the adsorption of additional proteins pre sent in the medium. This study asked whether fibronectin could be immobiliz ed in a controlled manner to a hydrophobic surface with a chemically modifi ed triblock surfactant. ELISA studies indicated that variation of the solub le fibronitctin concentration used for immobilization could be used to cont rol the amount of fibronectin immobilized to the surface. Furthermore, fibr oblasts seeded on these surfaces in 10% serum-containing medium atttched an d spread as a function of the amount of immobilized fibronectin. Surfaces t reated with unmodified surfactant did not support cell attachment, suggesti ng that cell attachment and spreading were primarily regulated by the immob ilized fibronectin with minimal interference from adsorption of serum prote ins. Together, these results suggest that covalent immobilization to Pluron ic(TM) F108 provides a method for studying cellular responses to cell adhes ive proteins with little interference from competing adsorbates, even in th e presence of complex biological fluids such as serum. This technique may b e applicable to a variety of existing hydrophobic biomedical polymers as a basic scence tool as well as for influencing cell behavior at implant inter faces.