Biomedical Engineering Reference
In-Depth Information
Chapter 11
Design Concept of Topographical
and Mechanical Properties of Synthetic
Extracellular Matrix to Control
Cell Functions and Fates Through
Actin Cytoskeletal Modulation
Physiological roles of the actin cytoskeletal system are dynamic memory for guiding
cell fate, as well as mechanical support and endogenous force generation for cell
shape changes and cell migration. The actin cytoskeleton dynamically reorganizes
to maintain mechanical homeostasis in response to topographical and mechanical
cues provided by the extracellular environment. Thus, a synthetic extracellular
matrix (ECM) with designed topographical and mechanical properties can be uti-
lized to control a variety of cellular processes through modulation of the actin cyto-
skeleton. This chapter proposes a design concept of ECM niche to control cell
migration, proliferation and differentiation by focusing on the physiological roles of
actin cytoskeletal system, and describes its application to biomedical engineering.
11.1
Introduction
As emphasized in the previous chapters of this topic, a major physiological role of
the actin cytoskeleton is to provide mechanical support and a driving force for
changes of the cell shape and for cell migration. In addition, the long-lived actin
cytoskeletal structure is thought to serve as an epigenetic determinant of cell fate
(Fletcher and Mullins
2010
), particularly, for proliferation and stem cell
differentiation.
The cell modulates the delicate force balance between contractility of the endoge-
nous actin cytoskeleton and exogenous mechanical forces transmitted bi-directionally
between a cell and the extracellular matrix (ECM) (Sun and Fu
2013
). Instantaneous
imbalance in the mechanical homeostasis is adjusted through reorganization of the
actin cytoskeleton and of the cell-ECM adhesion complex. Thus, a synthetic ECM
engineered as a source of topographical and mechanical cues is expected to be effec-
tive at modulation of the actin cytoskeleton.
