Sub‐micron and nanoscale feature depth modulates alignment of stromal fibroblasts and corneal epithelial cells in serum‐rich and serum‐free media

Abstract

Topographic features are generally accepted as being capable of modulating cell alignment. Of particular interest is the potential that topographic feature geometry induces cell alignment indirectly through impacting adsorbed proteins from the cell culture medium on the surface of the substrate. However, it has also been reported that micron-scale feature depth significantly impacts the level of alignment of cellular populations on topography, despite being orders of magnitude larger than the average adsorbed protein layer (nm). In order to better determine the impact of biomimetic length scale topography and adsorbed protein interaction on cellular morphology we have systematically investigated the effect of combinations of sub-micron to nanoscale feature depth and lateral pitch on corneal epithelial cell alignment. In addition we have used the unique properties of a serum-free media alternative in direct comparison to serum-rich medium to investigate the role of culture medium protein composition on cellular alignment to topographically patterned surfaces. Our observation that increasing groove depth elicited larger populations of corneal epithelial cells to align regardless of culture medium composition and of cell orientation with respect to the topography, suggests that these cells can sense changes in topographic feature depths independent of adsorbed proteins localized along ridge edges and tops. However, our data also suggests a strong combinatory effect of topography with culture medium composition, and also a cell type dependency in determining the level of cell elongation and alignment to nanoscale topographic features.

Phenomenon of “contact guidance“ on the surface with nano-micro-groove-like pattern and cell physiological effects

“…However, with the same "ridge" width, the deeper the groove, the more pronounced "contact guidance occurred". And the results were in accordance with other researches; i.e., when the "ridge" width is fixed, the groove depth was the predominant factor in determining the occurrence of "contact guidance" [12,14,15,23] . Apart from the factors such as depth and width, researchers further investigated the threshold scale that can cause "contact guidance".…”

Arrays of topographically and peptide-functionalized hydrogels for analysis of biomimetic extracellular matrix properties

“…We have previously demonstrated that feature depth of topographic features is a significant parameter, where increased groove depth resulted in an increase in the number of cells elongating and aligning in the direction of the grooves. 32 It is important to note, however, that differences in feature depths ranging from 200 to 450 nm, as measured by AFM (absolute or not) in this study, would not have elicited significantly different cellular responses.…”

Determinants of cell–material crosstalk at the interface: towards engineering of cell instructive materials

“…Increasing feature height, while keeping constant inter-feature length, causes the space between adjacent grooves to become impervious to the cell membrane and integrins and therefore a decrease in adhesion stability occurs [70,71]. Analogous results have been observed on substrates presenting arrays of nanometric pits.…”