Biomedical Engineering Reference
In-Depth Information
7
Minimum Reactants Required for
Synthesis of Skin and Peripheral Nerves;
Extension to Tissues of Other Organs
7.1
Reaction Diagrams
In the preceding two chapters, we reviewed in great detail the conditions under
which component tissues in skin and peripheral nerves, as well as the organs them-
selves, have been synthesized. The data reviewed in the preceding chapters were
obtained using anatomically well-defined defects in skin (full-thickness excisional
defect) and in peripheral nerves (complete transection of nerve). Nevertheless, the
reactants employed, not all of them successful in yielding new tissues, have in-
cluded many types of solutions of proteins, cell suspensions, synthetic polymers,
and natural matrices, as well as grafts and tubes. Furthermore, these reactants were
added to media of various types and were cultured over a range of time intervals (in
vitro); or they were directly implanted to the anatomically well-defined defect (in
vivo). Products resulting from these processes resembled the desired tissue or organ
more or less in structure and function. Clearly, with the exception of the type of
injury studied, which was anatomically well-defined, these processes were studied
by the various investigators under conditions that were anything but standardized.
At first glance, it appears to be very difficult to generalize on these diverse data
in order to answer questions such as: Which of the reactants used were actually
necessary to yield the desired tissue components of skin or peripheral nerves, or the
organs themselves? Which was the simplest protocol that led to the desired synthe-
sis? Are in vivo conditions (typically more complicated than in vitro) required to
achieve any of these syntheses? Are the reaction conditions required for synthesis
of skin similar to those for synthesis of peripheral nerves? Do any such similarities
generate rules that can be hypothetically used to synthesize other organs?
A convenient way to sort through the complex information is to adopt a conven-
tion found to be very useful by chemists about two centuries ago. It consists in apply-
ing the systematics of synthetic chemistry, ordinarily used to describe the prepara-
tion of chemical compounds, in order to describe the formation of a tissue or organ.
The resulting simplified symbolism is easy to use and appears to be very effective
in sorting out the essential information pertinent to synthesis of tissues and organs.
