Replication of biocompatible, nanotopographic surfaces.

The ability of cells to sense and respond to nanotopography is being implicated as a key element in many physiological processes such as cell differentiation, immune response, and wound healing, as well as in pathologies such as cancer metastasis. To understand how nanotopography affects cellular behaviors, new techniques are required for the mass production of biocompatible, rigid nanotopographic surfaces. Here we introduce a method for the rapid and reproducible production of biocompatible, rigid, acrylic nanotopographic surfaces, and for the functionalization of the surfaces with adhesion-promoting molecules for cell experiments. The replica surfaces exhibit high optical transparency, which is advantageous for high-resolution, live-cell imaging. As a representative application, we demonstrate that epithelial cells form focal adhesions on surfaces composed of nanoscale ridges and grooves, and that the focal adhesions prefer to localize on the nanoridges. We further demonstrate that both F-actin and microtubules align along the nanoridges, but only F-actin aligns along the nanogrooves. The mass production of nanotopographic surfaces opens the door to the investigation of the effect of physical cues on the spatial distribution and the dynamics of intracellular proteins, and to the study of the mechanism of mechanosensing in processes such as cell migration, phagocytosis, division, and differentiation.