Cell Adhesion on Nanomater Scale Fibronectin Patterns: a Comparision of Breast Cancer Cells and Normal Breast Epithelial Cells

Abstract

Cell adhesion to extracellular matrix is an important process for both health and disease states. Surface protein patterns are topographically flat, and do not introduce other chemical, topographical or rigidity related functionality and, more importantly, that mimic the organization of the in vivo extracellular matrix are desirable. Previous work showed that vinculin and cytoskeletal organization are modulated by the size and shape of surface nanopatterns. However, a comparative and quantitative analysis on normal and cancerous cell morphology and focal adhesions as a function of micrometer scale spacings of protein nanopatterns was absent. Here, electron beam lithography was used to pattern fibronectin (FN) nanodots with micrometer scale spacings on a K-casein background (single active) on indium tin oxide (ITO) coated glass which, unlike silicon, is transparent and thus suitable for many light microscopy techniques. Exposure times were significantly reduced using the line exposure mode with micrometer scale step sizes. Micrometer scale spacings of 2, 4, 8 microns and gradients between FN nanodots modulated cell adhesion for both breast cancer and normal mammary epithelial cells, through modification of cell area, cell symmetry, actin organization, focal adhesion number, size and circularity under both static and flow conditions. Overall, cell behavior was shown to shift at the apparent threshold of 4 μm spacing. Results showed that there were significant differences in terms of cell adhesion between breast cancer and normal mammary epithelial cells: Breast cancer cells exhibited a more dynamic and flexible adhesion profile than normal mammary epithelial cells.