Computational Methods in the Modeling of Scaffolds for Tissue Engineering - Computational Modeling in Tissue Engineering - page 103

Fig. 1 Tissue engineering process using biomaterial scaffold (modified from Liu et al. [ 6 ])

by the deliberate and controlled stimulation of selected target cells through a
systematic combination of molecular and mechanical signals'' [ 2 ]. The process of
creation of biological tissue needs an artificial substrate to guide the tissue and
control the cell response to the supply of specific molecular and mechanical sig-
nals. ''Scaffold'' is the denomination for the temporal artificial support. Generally
studies of biomaterial substrates are done in two-dimensions in order to evaluate
the cell-biomaterial interactions. However, it is desired that the scaffold substitutes
the defect or mimic the organs or tissues structures in a three-dimensional manner
so that it ensures the functions of the damaged tissues.
In the last decade the advances made in tissue engineering and scaffold research
have increased substantially [ 3 ]. These substantial changes in this scientific field
should generate a higher quality of life of people. However, the main barrier found so
far is related to the difficulties of translating scientific results into clinical applications.
Another problem is related with the high complexity of the biological processes that are
taking place and that are not well controlled or understood. The complexities and the
use of the human cells as a cell source make tissue engineering an expensive process
with usually a low reproducibility of the results at an industrial scale.
The requirements of a scaffold are multiple and different for each application.
Nonetheless some common characteristics can be found such as: a good network
of interconnecting pores, open channels capable to provide the oxygen and
nutrients to the cells inside the scaffold, an easy removal of the waste product and a
biocompatible material able to provide the appropriate mechanical strength and
biodegradable properties. Some of the characteristics and phenomenon involved in
tissue engineering are summarized in Fig. 1 . The intrinsic biomaterial properties in
relation to the scaffold architecture influence the affinity and response of the cells
within the scaffold. During the cell culture it is desirable (a) to know the forces
supported by the cells attached on the scaffold, (b) to study the distribution of cells
after seeding, (c) to study how occur cell migration, proliferation, and differenti-
ation, and (d) to study the influence of the mechanical stimuli on the cell response.
This complexity is further increased under in vivo conditions where the bioma-
terial degradation and tissue formation, and the adaptation of a new tissue with the
new blood vessel formation (angiogenesis) are combined.
Computational methods have been introduced in tissue engineering as tools to
comprehend and predict the phenomenon occurring inside scaffolds. Initially, the