Biomedical Engineering Reference
In-Depth Information
Structure and Biology of the Cellular
Environment: The Extracellular Matrix
Igor Titushkin, Shan Sun, and Michael Cho
1
Introduction
The extracellular matrix (ECM) represents a complex organization of macromol-
ecules that surrounds the cell and comprises the substratum onto which the cell
may be attached. The properties and functions of the ECM depend ultimately on
its structure, molecular components, architecture, and dynamic modulation.
Because the critical role of ECM involved in cell biology and physiology has long
been recognized, the structure and biology of the ECM have been extensively
studied (Yurchenco and Birk
1994
; Ayad et al.
1998
; Robert
2001
) . The diversity
found in the structure and organization of the ECM appears to be tissue specifi c
and regulates the properties and function of each tissue. The ECM was once
believed to provide mainly the structural support and tensile strength of the tissue.
It is now recognized that in addition to the role of mechanical stability, the ECM
also provides substrate for cell adhesion and migration and regulates cell differen-
tiation, metabolic activity, and cell-cell signaling, and therefore intimately
involved in cellular and molecular response and behavior of the cell. For example,
the ECM is found to harbor potent signaling cues, such as cytokines and growth
factors (Engel
2004
). Furthermore, the relationship between cell and ECM can be
considered bidirectional (Cukierman et al.
2001
; Geiger et al.
2001
; Labat-Robert
2004
; Yoon et al.
2005
): while ECM is known to infl uence the cell behaviors and
functions, the cell, in turn, modifi es local environment and remodels the ECM.
This ability of ECM to undergo remodeling plays an important role especially in
developmental tissue (Zagris
2001
; Trelstad
2004
) and wound healing (Schaffer
and Nanney
1996
; Tuan et al.
1996
; Cutroneo
2003
). In the context of tissue
I. Titushkin • S. Sun • M. Cho (
)
Department of Bioengineering, University of Illinois at Chicago,
851 S. Morgan St. (M/C 063) , Chicago , IL 60607 , USA
e-mail: mcho@uic.edu
