Biomedical Engineering Reference
In-Depth Information
Fig. 9.5
Schematic
illustration that the substrate
consists of a fl at surface and a
grooved surface with
intersecting grooves (Miyoshi
et al.
2010
) (Adapted with
permission from Elsevier
Ltd.: [Biomaterials],
copyright (2010))
surface with the intersecting grooves. On all surfaces with the intersecting grooves, the
groove spacing is 5
μ
μ
m, and the groove depth is 20
m. The width of the grooves is
μ
μ
μ
either 1.5
m groove widths allow
a single cell to experience multiple orthogonal grooves at the same time, thus, the
effect of the groove width on cell migratory behavior can be investigated by using
these two different grooved surfaces.
m (IS-W1.5) or 4
m (IS-W4). Both 1.5 and 4
9.4.2
Cell Migratory Behavior at the Boundary
with Intersecting Grooves
The response of cells encountering intersecting grooves can be classifi ed into two
groups, “stay” and “turn”, according to the cell migration paths.
A representative image sequence of stay-type response is shown in Fig.
9.6a
. In
this case, cells encountering a grooved surface go straight and migrate into the
grooved surface (0-120 s). Once in the grooved surface, cells associate preferentially
with pillars and pause to migrate by anchoring themselves to the pillars (180-420 s).
After pausing for some minutes, a lamellipodium starts to extend to one of the
neighboring pillars, and cells move across a groove between the pillars (420-480 s).
Then, cell migration pauses again (480-540 s). The duration of pausing varies from
several minutes to tens of minutes. As shown in Fig.
9.7
, over 50 % of cells exhibit a
stay-type response to IS-W4 grooves. Whether cells turn or not at the boundary with
the grooved surface depends on the angle of approach of cells to the grooved sur-
face. The details are described in Chap.
10
.
In Fig.
9.6b
, a typical sequence of turn-type responses is shown. After the
leading lamella encounters the front edge of a groove, the cell body moves
straight to the grooved surface, until half of the cell body moves the grooved
surface (0-150 s). Then, the cell body is squashed into a ball-like shape on the
groove (150-250 s). Subsequently, cells form a new lamella on the fl at surface,
returning to the original shape (300-450 s). Finally, the cell changes their migratory
direction and turn back to the fl at surface. This behavior is similar to the response
