| Mechanical load and stress are exerted upon heart muscle tissues in vivo, leading to changes in cellular biochemistry and physiology. To understand the fundamental mechanism of mechanical transduction at the cellular level, physiologically relevant models of cells in vitro are made, using stretchable commercial grade medical silicone polymer. The surface property of silicone are modified by plasma and silane treatment followed by covalent binding of a 15-residue peptide---acetyl-CGGEGYGEGRGDSPG-amide. The surface is characterized by x-ray photoelectron spectroscopy, spectrochemical analysis, radiolabelling and amino acid analysis. The GRGDSP peptide bound silicone surface shows enhanced binding of rat neonatal heart fibroblasts and myocytes cells, compared to amine-functionalized and unmodified silicone surfaces. To eliminate non-specific adhesion of proteins from the cell culture medium, hydrophilic moeities such as polyethylene glycol (PEG) can be bound to a surface. A solid phase synthesis method is described that adds thiol group to PEG, facilitating PEG functionalization of silicone. Fibroblasts growth on PEG functionalized silicone is then evaluated. Finally, a novel method is described that allows 3D control of both chemistry and morphology on silicone by a series of wet chemical steps. Protein functionalized, micron sized beads are covalently bound to a flat silicone surface, which is subsequently functionalized with a distinct chemical group such as polylysine. Fibroblast integrin, physical responses and adhesion are examined as a function of varying the ligands on the beads. |
