The beta integrins and cytoskeletal nanoimprinting

"Nanoimprinting", whereby topographical features are directly imprinted on or in cells, has recently been documented. The mechanism(s) underlying this may explain the cause of cell behavioural alterations as a result of contact with nanotopography. Integrin-mediated cell-substrate adhesions are likely to play a key role in this phenomenon due to their involvement in bidirectional signalling between extra- and intracellular environments. We describe the effects of blocking beta1 and beta3 integrin subunits on the ability of the cytoskeleton to conform to colloidal-derived nanotopography. Scanning electron and atomic force microscopy were used to characterise substrate nanofeatures. Nanofeature circularity was calculated relative to substrate topography and the cytoskeleton of cells cultured on patterned and planar surfaces in the presence/absence of beta1/beta3 integrin antibody. Cross-correlation investigations were similarly conducted by producing a target image relative to individual topographical nanofeatures. This was then compared with cytoskeletal patterning in the presence/absence of beta integrin antibodies. Inhibiting the beta1 subunits increased the ability of fibroblasts to nanoimprint, while inhibiting the beta3 subunit reduced nanoimprinting of the topography to the cell. Fibroblasts cultured on planar substrates also expressed some features sharing similarities with those observed in cells on the nanotopography, indicating an inherent cytoskeletal nanopatterning at high resolution.