Biomedical Engineering Reference
In-Depth Information
14.3.3
Need for Scaffolds
It should be noted that the natural ECM, a major component of connective tissues,
is not a template or scaffold in organogenesis of embryo, but simply a product
accompanying the embryogenesis. This suggests that it is not reasonable to regard
a scaffold as an artifi cial ECM, although the current major topic in scaffold research
is to mimic the natural ECM.
In discussing the rational design of scaffolds, it is necessary and pertinent to
divide scaffolds into two groups (Scaffold type I and type II) on the basis of the
cells to be seeded in scaffolds. Scaffold type I is used for differentiated cells includ-
ing fi broblast, osteoblast, and chondrocyte, as represented in Figure 14.3. Figure
14.4 demonstrates Scaffold type II that is used for not yet fully differentiated pro-
Produced ECM
Biodegradable polymer
Implantation
Paracrine, autocrine, or
endocrine factor
Multiplied cell
Seeded cell
Figure 14.3
Scaffold type I for differentiated cells.
Trace of scaffold
Pore
Seeded stem cell
Scaffold surface
Endothelial cell
Paracrine, autocrine, or
endocrine factor
Smooth muscle cell
Implantation
Fibroblast
Regenerated
tissue
Trace of stent
Biodegradable
mechanical support
(stent)
Figure 14.4
Scaffold type II for progenitor cells.
