Page 256 - Advances in Biomechanics and Tissue Regeneration

CHA PTE R

13

Multidimensional Biomechanics Approaches

Though Electrically and Magnetically Active

Microenvironments

,¶
,†
‡
S. Ribeiro* , C. Garcia-Astrain , M.M. Fernandes* , S. Lanceros-
Mendez ‡,§ , and C. Ribeiro* ,¶
†
*Center/Department of Physics, University of Minho, Braga, Portugal Centre of Molecular and Environmental Biology
‡
(CBMA), Universidade do Minho, Braga, Portugal BCMaterials, Basque Center for Materials, Applications and
§
Nanostructures, UPV/EHU Science Park, Leioa, Spain IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
¶
CEB—Centre of Biological Engineering, University of Minho, Braga, Portugal

13.1 RELEVANCE OF ELECTRIC AND MECHANICAL CLUES FOR TISSUE
ENGINEERING

Tissue engineering approaches usually involve a biocompatible material in combination with stem cells and differ-
ent stimuli to repair tissues or organs. Cell adhesion is influenced by several parameters such as the surface chemistry
of the scaffold and its surface charge or topography. To induce stem cell differentiation to the desired lineage, stem cells
require extracellular stimuli, such as chemical (growth factors) and physical clues (i.e., mechanical stimulation). Phys-
ical signals are particularly relevant, as cell development is influenced by these stimuli and cell activity can be mod-
ulated in in vitro models that mimic the body microenvironment. Moreover, cell adhesion, proliferation, and
differentiation can be also regulated by using active scaffolds that provide the appropriate environment for specific
cell responses. The effect of external stimuli over cell attachment is also a key point, since focal adhesions are the pre-
dominant mechanism by which cells mechanically connect to and apply traction forces on the extracellular matrix
(ECM) [1]. Although the cellular response to electrical stimuli remains still unknown, some regulatory membrane pro-
teins and enzymes are sensitive to electric fields. When a cell attaches to a surface, it receives information from the
environment by means of ion channels and receptors present in the membrane and starts developing focal
adhesions [2].
The relevance of electrical phenomena in the human body was realized in the 18th century by von Haller and later
by Galvani and Volta who demonstrated the dependence of muscles and nerve cells on electricity [3]. Major func-
tions of cells, such as metabolism and growth, are influenced by electrical processes at different stages. Cells maintain
a difference in potential and modulate it when necessary, can switch current on and off, and vary current flow
or store charge [4]. Among the different clues determining tissue functionality, electrical and electromechanical ones
are essential for tissues such as bone or muscle [5]. Further, movement and migration can be guided by electric fields
in a variety of different cell types such as corneal, epidermal, and epithelial cells [6–9]. Moreover, these electric
fields can also modulate the phenotypes of vascular endothelial cells, regenerate nerve fibers, and influence ligament
healing [10–12].

Advances in Biomechanics and Tissue Regeneration 253 © 2019 Elsevier Inc. All rights reserved.
https://doi.org/10.1016/B978-0-12-816390-0.00013-3