Biomedical Engineering Reference
In-Depth Information
Fig. 2.4
The components of tissue engineering and their role in achieving tissue regeneration. Cells
are the basic unit of tissues, they proliferate and generate the tissue matrix; scaffolds are engineered
from biomaterials and host the cells provisionally during regeneration process; growth factors and
physical stimulation affect the cell function and tissue formation, while bioreactors can mimic the
in vivo conditions by supplying controlled environment and conditions for cell culturing
2.4 Tissue Engineering and Regenerative Medicine Strategies
2.4.1 The Components: Cells, Scaffolds, Growth Factors,
and Bioreactors
The different components of tissue engineering and their role in achieving tissue
regeneration are illustrated in Fig.
2.4
. Cells are the basic unit of tissues that generate
the tissue matrix, while scaffolds are engineered from biomaterials and host the cells
during the regeneration process. Growth factors and physical stimulation contribute
to the tissue regeneration with their influence on the cell function, while bioreactors
canmimic the in vivo conditions for cell culturing.
Cells
can be categorized as mature
differentiated and stem cells. Mature differentiated cells perform highly specialized
functions in a specific tissue. Stem cells are in an undifferentiated state having the
ability to self-renew and differentiate into specialized cell types to create new tissues.
Stem cells can be classified by the tissue type they are isolated from: embryonic [
35
]
and adult stem cells [
36
]. Embryonic stem cells are isolated during the embryonic
stages of development and thus, have a greater natural potential, whereas adult stem
cells are relatively more specialized and partially differentiated. Stem cells can also
be classified by their potential based on their natural tendency: totipotent, pluripotent,
multipotent and unipotent. Totipotent and pluripotent stem cells have an embryonic
origin, and totipotent stem cells possess the greatest potential since they have the
ability to differentiate into all cell types in the body. Multipotent and unipotent stem
