Influence of systematically varied nano-scale topography on cell morphology and adhesion

The types of cell-matrix adhesions and the signals they transduce strongly affect the cell-phenotype. We hypothesized that cells sense and respond to the three-dimensionality of their environment, which could be modulated by nano-structures on silicon surfaces. Human foreskin fibroblasts were cultured on nano-structures with different patterns (nano-post and nano-grate) and heights for 3 days. The presence of integrin α5, β1, β3, paxillin and phosphorylated FAK (pFAK) were detected by western blot and immunofluorescence. Integrin β3 exhibited stronger signals on nano-grates. pFAK and paxillin were observed as small dot-like patterns on the cell-periphery on nano-posts and as elongated and aligned patterns on nano-grates. Collectively, our observations highlighted the presence of focal (integrin β1, β3, pFAK, paxillin), fibrillar (integrin α5, β1) and 3-D matrix (integrin α5, β1, paxillin) adhesions on nano-structures. The presented nano-structures offer interesting opportunities to study the interaction of cells with topographical features comparable to the size of extracellular matrix components.