No abstract

Culturing cells on gradient nanopatterns provides a useful tool to explore cellular adhesion to mimics of the extracellular matrix or screen for cellular responses to nanopatterns. A method is presented to fabricate complex gradient protein patterns based on hole-mask colloidal lithography, which can generate nanopatterns in multiple materials and of multiple shapes. Gradients of gold structures were functionalized to form gradients of protein nanopatterns of different shapes (bars, dot pairs, and rings), where a key parameter was systematically varied in each gradient. Cells were grown on vitronectin nanopatterns, showing differential adhesion (spread area/focal adhesion size) along the gradients.

The novel nanofiber patterns developed in this study, via ENL, mimic the geometry and continuity of natural matrices found in the stroma of tissues, whilst preserving a quasi-2D character (to facilitate imaging and for comparison with other 2D systems such as micropatterned monolayers and circular nanopatches generated by colloidal lithography). These results demonstrate that the nanoscale geometry of the ECM plays an important role in regulating cell adhesion and that this is modulated by integrin expression. This is an important finding as it implies that the knowledge of the biochemical context underlying the integrin-mediated adhesive machinery of specific cell types should allow better design of biomaterials and biointerfaces. Indeed, changes in integrin expression are often associated with the control of cell proliferation and differentiation.