Computational Methods in the Modeling of Scaffolds for Tissue Engineering - Computational Modeling in Tissue Engineering - page 118

Fig. 13 Scheme
representing the main
methods applied for in tissue
engineering scaffold
deformation), there was not a noticeable effect on angiogenesis. Similar vessel
networks were observed in both cases of strain (Fig. 12 ). The angiogenic process
was mostly driven by the actual porosity and permeability of the scaffold rather
than by the load magnitude.
6 Conclusions and Future Trends
In this chapter, computational methods used in the modeling of scaffolds for tissue
engineering were illustrated through some examples selected from the literature.
Figure 13 shows a summary of the different schemes used to model scaffolds.
Initially the characterization of the scaffold is based on image acquisition and
treatment in order to obtain the morphological parameters. These parameters
(porosity, pore shape, pore size) can be designed previously (CAD) when a rapid
prototyping method is used in the fabrication process; but the real structure can be
assessed using micro-CT scanning. In order to control the mechanical properties of
the scaffold; displacement or load are applied to simulate the experiment condition
and the effective stiffness can be computed. Generally, the FEM is applied in the
characterization of the mechanical integrity of scaffold, including the possible
simulation of scaffold degradation. The irregular scaffold morphology leads to
heterogeneous distributions of stimuli induced from the solid phase. The best
control of the mechanical stimuli can be obtained using RP scaffolds. Studies
with RP scaffolds allow to develop methods such as homogenization were the
optimization of the macro-scaffold properties are related with the micro pore
properties.
For the evaluation of mass flow inside the scaffold, computational fluid
dynamic (CFD) simulations can be used. Generally, the fluid shear stress is defined
as the stimulus acting on the scaffold wall to characterize the fluid flow. In the
literature different ranges of stimuli are found and a consensus must be found, but
in principle using this methodology it is possible to control precisely the design of
the size and shape of the scaffold pores. The mechano-biological phenomenon can
also be simulated from the perspective that the porous scaffolds have two phases