Biomedical Engineering Reference
In-Depth Information
a
b
(Perspective view)
(Perspective view)
Actin
filament
Adhesion
complex
Curved cavity
(Side view)
(Side view)
Fig. 11.6
Different adhesion modes of different cell types in a curved feature. (
a
) Fibroblasts that
have well-mature focal adhesions and well-organized cytoskeletal structure typically stretch and
adhere to etched cavities at focal adhesions, whereas (
b
) cancer cells, deforming easily due to their
impaired cytoskeleton, adapt to the curved surfaces and exhibit relatively diffuse adhesion, based
on the results by (Nikkhah et al. 2009)
11.3.1.6
Cell Type-Specifi c Sensitivity to Topographical Features
The sensitivity of cells to topography depends on cell type (Miyoshi et al.
2010
,
2012
; Biela et al.
2009
; Nikkhah et al.
2009a
,
b
,
2010
; Friedl and Wolf
2010
; Kwon
et al.
2007
; Clark et al.
1987
; Fisher and Tickle
1981
). Fibroblasts (Fig.
11.6a
) and
malignant cancer cells (Fig.
11.6b
) adhere to silicon curved cavities in different
morphology (Nikkhah et al.
2009a
,
2010
). The basis of this phenomenon is differ-
ence in sensitivity between the different cell types to topographical features.
The strength of adhesion and of mechanical feedback that a cell senses on integ-
rin ligation (Trappmann et al.
2012
) determines how much the cell is constrained by
ECM; thus, this factor will be a primary endogenous determinant of sensitivity of
the cell to micro-/nanotopographical features. Generally, transformed cells are
insensitive to the topographical features because of a noticeable decline in the
mechanical feedback, and they exhibit uncontrolled growth independent of the
ECM architecture (Wang et al.
2009
).
In designing topography for well-defi ned modulation of actin cytoskeleton, we
should take into account exogenous parameters to tune how much the cell is con-
strained by the synthetic ECM.
11.3.2
Mechanical Cue
As discussed in Sect.
11.3.1.6
, the effectiveness of micro-/nanotopography as a
structural constraint to modulate actin cytoskeleton varies by cell type because of
cell type-specifi c sensitivity to topographical features. To cope with this cellular
