Abstract:
The basement membrane possesses a rich 3-dimensional
nanoscale topography that provides a physical stimulus,
which may modulate cell-substratum adhesion. We have
investigated the strength of cell-substratum adhesion on
nanoscale topographic features of a similar scale to that of
the native basement membrane. SV40 human corneal
epithelial cells were challenged by well-defined fluid shear,
and cell detachment was monitored. We created silicon
substrata with uniform grooves and ridges having pitch
dimensions of 400-4000 nm using X-ray lithography. Factin
labeling of cells that had been incubated for
24 hours
revealed
that the percentage
of aligned and elongated cells
on
the patterned
surfaces was the same regardless
of pitch
dimension.
In contrast, at the highest fluid shear,
a biphasic
trend
in cell adhesion was observed
with cells being most
adherent
to the smaller features.
The 400 nm
pitch had the
highest percentage of adherent cells at the end of the
adhesion assay. The effect of substratum topography was
lost for the largest features evaluated, the 4000 nm pitch.
Qualitative and quantitative analyses of the cells during
and after flow indicated that the aligned and elongated cells
on the 400 nm pitch were more tightly adhered compared
to aligned cells on the larger patterns. Selected experiments
with primary cultured human corneal epithelial cells
produced similar results to the SV40 human corneal
epithelial cells. These findings have relevance to
interpretation of cell-biomaterial interactions in tissue
engineering and prosthetic design.
