Deflection Induced Cellular Focal Adhesion and Anisotropic Growth on Vertically Aligned Silicon Nanowires with Differing Elasticity

Abstract

Cellular adhesion and growth on substrates with differing surface topography are known to induce unusual cell behaviors. Here, we investigated the adhesion and growth of human embryonic kidney 293T cells on vertically aligned silicon nanowires. Varying the diameter of nanowires affected their elasticity, which in turn caused variations in cell morphology and adhesion. Calculation of their elastic modulus revealed that long and thin nanowires are easier to deflect and thus provide more focal adhesion sites for adherent cells. And, induced mechanical tension triggered cellular anisotropic growth in the direction of tension, creating a greater rate of filopodium growth than was observed with a bare glass substrate devoid of mechanical tension. This nanotopographical approach provides important insights into the role of artificial substrates in the modulation of cell behavior and a conceptual framework for further analysis of substrate-induced changes in cellular activity.