Computational Methods in the Modeling of Scaffolds for Tissue Engineering - Computational Modeling in Tissue Engineering - page 107

Fig. 3 a Examples of distribution of octahedral shear strain in two samples for CaP cement (left)
and glass (right) scaffold morphologies (modified from Lacroix et al. [ 9 ]). b Major strain
distribution in RP pores; the zones under tension or compression strain are delimited; prism
hexagonal shape with 70% of porosity (left), gyroid pore structure with 70% of porosity (middle),
and gyroid pore shape distributed gradually through the height of scaffold (global porosity equals
70%) (right) (data from Olivares et al. [ 5 ])
The mechanical parameters computed in the scaffold surface are considered as
the stimuli or signals felt by the cells attached. Dependent on the stimuli magni-
tude (strain for example), the stimuli will alter cell proliferation or phenotype
differentiation. Generally, for bone tissue engineering applications a compressive
load is applied to determine the strength and the strain distribution in the scaffold
wall surface (see Fig. 3 ). The effect of mechanical stimuli was studied through
micro-FE models for macroporous CaP cement and for a porous glass ceramic
scaffold. The octahedral shear strain distribution on a two dimensional section of
both samples is shown in Fig. 3 a; higher strains are found in areas close to the
pores with magnitudes up to 0.75% for the application of a compressive strain of
0.5% [ 9 ]. The strain distribution throughout the section is quite inhomogeneous
due to the inhomogeneous pore distribution.
Under a compressive load equivalent to a uniaxial strain of 0.5%, the structures
shown in the Fig. 3 b presented a higher proportion of material experiencing