Evaluation of polydimethylsiloxane modification methods for cell response

Many methods exist in the literature to modify surfaces with extracellular matrix (ECM) proteins prior to cell seeding. However, there are few studies that systematically characterize and compare surface properties and cell response results among modification methods that use different bonding mechanisms. In this work, we compare cell response and physical characterization results from fibronectin or laminin attached to polydimethylsiloxane (PDMS) elastomer surfaces by physical adsorption, chemisorption, and covalent attachment to determine the best method to modify a deformable surface. We evaluate modification methods based on completeness and uniformity of coverage, surface roughness, and hydrophilicity of attached ECM protein. Smooth muscle cell adhesion, proliferation, morphology, and phenotype were also evaluated. We found that chemisorption methods resulted in higher amounts of protein attachment than physical adsorption and covalent bonding of the ECM proteins. Cell response to protein-modified surfaces was similar with respect to cell adhesion, area, aspect ratio, and phenotype. When all the data are considered, the chemisorption methods, most notably silane_70, provide the best surface properties and highest cell proliferation.