Biomedical Engineering Reference
In-Depth Information
under a light weight. Then, the stamped surface is rinsed twice with distilled
water, followed by incubation for 15 min or longer with an adhesion suppressing
protein or polymer such as PLL-g-PEG dissolved in an appropriate buffer. Since
PLL-g-PEG do not adsorb on stamped fi bronectin patterns, only the patterns remain
adhesive while remaining areas become cell repellant. We refer to the spacing
between two adjacent fi bronectin islands as “adhesion-suppressed gap” (or simply
a “gap”). By varying gap-length, it is possible to investigate cell migration on a
non-uniform substrate, and to determine how cells overcome adhesion barriers
during migration.
Figure
8.1a
shows a schematic of a micropatterned surface consisting of rectangular
fi bronectin patterns, the size of each is a × b = 18 × 38
m. The width of the interca-
lating space between the patterns, i.e. adhesion-suppressed gaps is:
d
= 3, 5, 7, and
9
ʼ
m. Figure
8.1b
shows a microscopic image of a regular fi bronectin micropatterns
embodied on a glass substrate. The white rectangular patterns are the stamped
adhesive areas while the remaining dark areas are PLL-g-PEG adsorbed adhesion-
suppressed gaps. To patterns shown, a mixture of fi bronectin and fl uorescently
labelled fi bronectin (labelled with Alexa Fluor 546) was used at ratio of 1:3, respec-
tively. Cell migration tends to occur along the pattern rows in the direction shown
by the arrow in Fig.
8.1a
.
ʼ
Fig. 8.1
Micropatterning of adhesion protein for controlling cell adhesion (Okeyo et al.
2011
).
(
a
) Schematic illustration of a rectangular micropattern array (
white rectangles
) and pattern
dimension. (
b
) An actual image of an array of fi bronectin micropatterns (
white rectangles
) on a
glass surface stamped with a PDMS stamp. The dark background represents PLL-g-PEG-adsorbed
adhesion-suppressed areas. The image was obtained by stamping the surface of a glass substrate
with a mixture of fi bronection and Alexa 546 labelled fi brinogen at a ratio1:3 (Adapted with
permission from Springer, Part of Springer Science + Business Media: [Cellular and Molecular
Bioengineering], copyright (2011))
