Biomedical Engineering Reference
In-Depth Information
Table 16.1
Advantages and disadvantages of different approaches used for cardiovascaular repair
Cardiovascular regeneration
strategy
Advantages
Disadvantages
Cell therapy
Skeletal myoblasts
Fetal and neonatal
cardiomyocytes
Endothelial cells
Vascular smooth muscle cells
Hematopoietic stem cells
Mesenchymal stem cells
Endothelial progenitor cells
Cardiac stem cells
Embryonic stem cells
Less invasive
Does not provide support to
cells or the heart, poor
integration with the host heart,
apoptosis and cell death,
inappropriate cell numbers/
density
Layered cell sheets
Non-immunogenic, good cell
density
Poor mechanical support, poor
cell coupling with the host tissue
Decellularized hearts
Provides a native-like
environment for
cells, good Cell numbers,
enhanced mechanical stability
Limited availability, more difficult
implantation techniques, more
immunogenic
Scaffolds
a
Biological
Better interactions with the cells,
non-toxic degradation products
Rapid degradation kinetics,
lack of sufficient mechanical
support to the cells, potential
contamination of materials from
animal tissue
Synthetic
Porosity, degradation time, and
mechanical characteristics can
be manipulated for specific
applications, physicochemical
and mechanical properties
comparable to those of
biological tissues, bioactive
compounds may be integrated
in the matrix.
Not physiological, does not
interact as favorably as
biologically derived scaffolds,
Biodegradation may induce
inflammatory responses
a
Biological and synthetic scaffolds can be fabricated into porous scaffolds, hydrogel scaffolds, microsphere
scaffolds, fibrous scaffolds, and composite scaffolds using different techniques.
includes the mobilization of endogenous stem or progenitor cells
in vivo
from the bone
marrow, to the damaged heart using specific cytokines and growth factors [6, 7]. Along with
bone-marrow cells, there is now accumulating evidence that the heart itself contains resident
cardiac stem cells (CSCs) with the capacity to differentiate into cardiac myocytes [8].
However, lack of sufficient numbers of cells that can be isolated from biopsies from patients
hinders the clinical utility of CSCs. Along with CSCs, embryonic stem cells (ESCs), and
induced pluripotent stem cells (iPSCs) have also been successfully explored for cardiomyo-
genic differentiation in several studies [9, 10].
Besides cardiomyocytes, two other cell types that are important to a properly functioning
heart are the vascular endothelial cell (ECs), which forms the inner lining of new blood
vessels, and the smooth muscle cell (SMCs), which forms the wall of blood vessels. The heart
has a large demand for blood flow and these specialized cells are important for developing
a new network of arteries to bring nutrients and oxygen to the cardiomyocytes after heart
