Stretching of fibroblast cells on micropatterned gelatin on silicone elastomer.

Here, the surface of silicone elastomer was modified with photo-reactive gelatin bearing azidophenyl groups. Two types of gelatin were prepared: one by coupling with azidoaniline and the other by coupling with azidobenzoic acid. The silicone surface was hydrolyzed by oxygen plasma and then gelatin was micropatterned on the surface using a photomask. The surface wettability was tuned by these treatments. The thickness of the gelatin layer was measured by a reflective confocal laser microscope, and it was regulated by the amount of gelatin. By immobilization of gelatin on the surface, cell adhesion was significantly enhanced and the enhancement was dependent on the type of modified gelatin. The stripe-pattern immobilization regulated the shape of cells adhered to silicone and high aspect elongation of the cell was observed. Although homogeneously immobilized gelatin showed the same tendency of fibroblasts (perpendicular orientation) against stretching stress as the non-immobilized surface, the micropatterned gelatin resisted such deformation by stretching stress. Microscopic observation showed that cytoskeleton fiber formed, oriented, and resisted the shape change by mechanical stress, although some reorganization of the cell cytoskeleton was observed. The present study shows that cytoskeleton fiber formation and orientation are important for the response to mechanical stress.