doi: 10.1242/10.1242/jcs.00383
Epithelial contact guidance on well-defined micro- and nanostructured substrates
Ana I. Teixeira1,
George A. Abrams2,
Paul J. Bertics3,
Christopher J. Murphy2,*,
and
Paul F. Nealey1,*,
1 Department of Chemical Engineering, School of Veterinary Medicine, University
of Wisconsin, Madison, WI 53706, USA
2 Department of Surgical Sciences, School of Veterinary Medicine, University of
Wisconsin, Madison, WI 53706, USA
3 Department of Biomolecular Chemistry, School of Medicine, University of
Wisconsin, Madison, WI 53706, USA

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Fig. 1. SEM images of human corneal epithelial cells. (A) Cell cultured on a
silicon oxide substrate patterned with 70 nm wide ridges, on a 400 nm pitch.
The groove depth was 600 nm. (B) Cell on a smooth silicon oxide substrate.
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Fig. 2. Distribution of orientation angles for cells cultured on substrates
patterned with 70 nm wide ridges and 600 nm deep grooves, on a 400 nm pitch
(circles), and for cells cultured on smooth silicon oxide substrates
(triangles). Each data point corresponds to the percentage of cells that have
orientation angles in the 10° angle interval up to the coordinate in the
x-axis.
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Fig. 3. Average cell elongations (cell length/cell breadth) of cells cultured on
substrates patterned with 70 nm wide ridges and 600 nm deep grooves, on a 400
nm pitch (circles) and of cells on smooth substrates (triangles). Average
elongation of nonaligned cells on patterned substrates (cells with orientation
angles between 10° and 90°) was equivalent to the average elongation
of cells cultured on smooth substrates. Cells with orientation angles less
than 10° were on average significantly more elongated than nonaligned
cells cultured on the patterned substrates or cells cultured on smooth
substrates.
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Fig. 4. Histogram of cell elongations for cells cultured on substrates patterned
with 70 nm wide ridges and 600 nm deep grooves, on a 400 nm pitch and for
cells cultured on smooth silicon oxide substrates. On the patterned substrates
more than 80% of the cells with elongations higher than 2 were aligned along
the substrate patterns. There was no correlation between cell elongation and
the percentage of cells with orientation angles less than 10° on the
smooth substrates.
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Fig. 5. Cells extended and retracted lamellipodia along the direction of the
patterns. (A-D) Time-lapse microscopy of a cell cultured on grooves and ridges
on a 400 nm pitch. The direction of the patterns can be clearly seen but, due
to the resolution of these images, the observed pitch is not correct. (E-H)
Cell on smooth silicon oxide. (A,E) 2.5 hours; (B,F) 9.5 hours; (C,G) 10.5
hours; (D,H) 12 hours after cell seeding.
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Fig. 6. Cells on smooth substrates had longer trajectories than cells on substrates
with grooves and ridges on a 400 nm pitch. Cell trajectories correspond to the
coordinates of the cells' centroids, recorded every 30 minutes from 2 hours
until 12 hours after seeding. The units of the axes are micrometers. (A) The
centroids of cells on patterned substrates were mostly stationary. (B) On
smooth substrates cells had random trajectories.
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Fig. 7. Percentage of cells cultured on patterned and smooth substrates that had
orientation angles less than 10° (designated aligned cells). On substrates
with 600 nm deep grooves, the percentage of aligned cells was constant on
patterns with pitches ranging from 400 nm to 2000 nm and decreased on 4000 nm
pitch patterns. On 150 nm deep grooves, cell alignment was equivalent on all
pattern pitches and was significantly lower than on 600 nm deep grooves, for
pitches up to 2000 nm.
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Fig. 8. Average projected cell areas of elongated cells (cell elongations higher
than 1.3) and round cells (cell elongations lower than 1.3) on substrates
patterned with 600 nm deep grooves and pitches between 400 nm and 4000 nm and
on smooth substrates (SiOx and TCPS). The culture medium was SHEM with 10%
FBS. The average projected cell areas of both elongated and round cells on any
of the patterned surfaces were lower than on the smooth surfaces.
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Fig. 9. Percentage of aligned cells in the presence or absence of FBS. When FBS was
not added to the culture medium the percentage of aligned cells was equivalent
on all pattern pitches and was significantly lower than in the presence of
serum, for pitches up to 2000 nm.
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Fig. 10. Average projected cell areas of elongated cells (cell elongations higher
than 1.3) and round cells (cell elongations lower than 1.3) on substrates
patterned with 600 nm deep grooves and pitches between 400 nm and 4000 nm and
on smooth substrates (SiOx and TCPS). The culture medium was SHEM and no FBS
was added. The average projected cell areas were similar on SiOx and on
TCPS.
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Fig. 11. SEM images of cells cultured on patterns with 400 nm pitch. (A) Cell
aligned along nanostructured substrate. (B) Cross-sectional image of cell
patterned substrate. (C) Filopodia extend along the top of ridges and bottom
of grooves. Lamellipodia protrude into the grooves at the cell edge along the
topographic patterns (bottom left) but bridge the grooves at the leading edge
of the cell.
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Fig. 12. SEM images of cells cultured on patterns with 4000 nm pitch. (A) Cell
aligned along microstructured substrate. (B) At the cell edges perpendicular
to the patterns, lamellipodia were able to adhere to the floor of the grooves
on 2100 nm wide grooves.
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Fig. 13. Cells stained for actin (red), vinculin (green) and the nucleus (blue) as
described in Materials and Methods. (A) Cell on a substrate with 600 nm deep
grooves and 70 nm wide ridges on a 400 nm pitch. (B) Cell on a substrate with
600 nm deep grooves and 1900 nm ridges on a 4000 nm pitch. A reflection image
of the substrates is included in the figure insets. (C) Cell on a smooth
silicon oxide substrate.
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Fig. 14. Average focal adhesion widths for cells cultured on smooth or patterned
silicon oxide substrates. The ridge width for each of the patterned substrates
is indicated (open squares).
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© The Company of Biologists Ltd 2003