Biomedical Engineering Reference
In-Depth Information
a
b
Protrusion
Protrusion
Contact guidance
Contact
guidance
Protrusion
suppressed
Protrusion
Tension
Contact guidance
Fig. 10.8
Mechanism of motility-based filtering by intersecting grooves (Miyoshi et al.
2010
).
(
a
) (
To p
) Cell with a higher angle of approach is exposed to multiple intersecting grooves at the
boundary. Preferential lamellar protrusions into the grooved surface (the
light red arrows
) due to
the contact guidance (the
green arrows
) result in attraction onto the grooved surface. (
Bottom
)
Actin fluorescent staining in a keratocyte attracted by the intersecting grooved surface (
w
= 5 ʼm;
s
= 3.5 ʼm). (
b
) For a cell with a lower angle of approach, only one side of the lamella is exposed
to the intersecting grooves at the boundary. The contact guidance (the
green arrows
) anchors the
side of the lamella on the grooved surface while allowing the other side on the flat surface to pro-
trude (the
red arrows
in the
bottom
figure). The increase in the intracellular tension (the
gray
arrow
) suppresses the protrusive activity perpendicular to the tension, which leads to the repulsion
of cells by the grooved surface (Adapted with permission from Elsevier Ltd.: [Biomaterials], copy-
right (2012))
Once on the grooved surface, the probability of the lamellar protrusions occurring
will be more likely in the direction along the grooves (Miyoshi et al.
2010
).
As summarized in Fig.
10.8
, the mechanism of efficient discrimination by the
intersecting grooves (
w
= 3, 4 ʼm;
s
= 5 ʼm) can be explained based on the contact
guidance and the resulting changes in endogenous force balance of migrating cells.
The effectiveness of the contact guidance is probably determined by the number
of intersecting grooves acting on the cell. As shown in Fig.
10.5a
, cells with a higher
angle of approach experience multiple intersecting grooves simultaneously, and
exhibit preferential lamellar protrusions into the grooves (green arrows in Fig.
10.8a
).
The guiding effectiveness of the intersecting grooves is enough to draw the cell
body into the grooved surface, and finally, result in cell attraction.
In contrast, the number of intersecting grooves acting on a cell is small (the
green arrows in Fig.
10.8b
, top) for cells with a lower angle of approach. In this
case, the guiding effectiveness of the intersecting grooves is not sufficient to draw
the cell body into the grooved surface and be limited to only one side of the lamella,
and the other side protrudes on the flat surface (Fig.
10.5b
, 0-160 s). This changes
