Promoted migration of fibroblast cells on low aspect ratio isotropic nanopore surface by reduced maturation of focal adhesion at peripheral region.

Cell migration plays fundamental roles in the development and maintenance of organisms such as wound healing and embryonic development, and cell migration is affected by the surrounding nanostructure of the extracellular matrix. Many researchers have developed various nanotopographical structures to investigate cell migration behaviors in response to the nanostructures, however, it is hard to draw firm conclusions about a relationship between surface topography and cell migration due to the contradictory results. Here, as one of the possible approaches to investigate the cell migration behaviors on the nanotopographies, we developed isotropic nanopore surfaces with high and low aspect ratios to have decreased and increased adherable areas, respectively. The nanopore surface with high aspect ratio had decreased adherable area of 86 % by providing the cells to adhere only on the top surface of the nanopores, while the nanopore surface with low aspect ratio had increased adherable area of 130 % by providing the cells to perceive both on the top surface and the bottom surface of the nanopores. In contrast to our expectation, the migration speeds of fibroblast cells were both promoted on the nanopore surfaces compared to the flat surface, regardless of the increase or decrease in adherable area. We found that the maturation of the focal adhesions (FAs) at the peripheral region is a key factor determining the adhesion strength of the fibroblast cells, which in turn affects cell migration. Our findings may widen our understanding of the cell migration behaviors on the nanostructured surface according to the formation of the FAs.