Biomedical Engineering Reference
In-Depth Information
Fig. 13.2
The basic 3 units/materials for a tissue construct, a biodegradable scaffold (
light gray
),
the tissue cells (
empty oval
), and the biomolecules (
circles
) acting as facilitators for the interaction
of the scaffold with the cells. Adapted from http://vascuplug.teltow.gkss.de
delivery of these cells to the targeted area. An abundance of pertinent literature
surveys is published [
405
,
406
]. At the same time, as it happens so often when the
initial enthusiasm overrides our better judgement, the need to better understand the
process of angiogenesis, stem cell science, and the utilization of molecular biology
and systems biology tools has emerged as mandatory for a deeper comprehension
of tissue development and control [
407
].
A simplified scheme for tissue engineering, involving biomaterials, is the fol-
lowing:
(3D porous biomaterial scaffold)
C
C
D
(tissue
construct)
. An example is shown in Fig.
13.2
. This scheme implies that fully orga-
nized and mature tissues must be created
ex vivo
, outside the body. Subsequently,
these tissues have to be transplanted and functionally integrated in the needed site.
Such a strategy involves three great challenges: (1) generation of functional tissues,
(2) transplantation in a manner that preserves their viability and function of the
cells, and (3) biological and mechanical fixation and integration with surrounding
tissue [
405
].
While a few cases involve thin tissue grafts, such as skin or corneal tissue, there-
fore not necessitating the existence within the graft of a vascular system for the
transport of nutrients and products of metabolism, and cartilage is physiologically
avascular, the majority of applications requires three-dimensional structures as well
as a developed functioning vascular system for the survival of the graft.
Of course, the three key players in this story: scaffolds, cells, and biomolecules,
are in a constant dialogue and interrelate to each other in particular ways for each
specific tissue or organ. We shall briefly examine them separately, with emphasis on
the scaffolds.
(cells)
(growth factors)
