The body cannot heal bone fractures surpassing 2 cm, so nowadays, graft surgery is the
only available treatment. Nonetheless, this entails serious risks such as immune rejection,
second medical interventions, and cross-infection. Therefore, bone tissue engineering has
arisen as an alternative approach able to solve this problem. Bone tissue engineering
provides temporary mechanical support for bone regeneration through an artificially
prepared extracellular matrix (i.e. scaffolds) to allow cell ...
The body cannot heal bone fractures surpassing 2 cm, so nowadays, graft surgery is the
only available treatment. Nonetheless, this entails serious risks such as immune rejection,
second medical interventions, and cross-infection. Therefore, bone tissue engineering has
arisen as an alternative approach able to solve this problem. Bone tissue engineering
provides temporary mechanical support for bone regeneration through an artificially
prepared extracellular matrix (i.e. scaffolds) to allow cell differentiation, proliferation,
and migration. To do so, global mechanical load (fluid or structural) is transferred as
stimuli to cells through the scaffold architecture. Adequate mechanical characteristics,
biomaterials and stimuli promote a proper mesenchymal cell differentiation to bone
phenotype.
The present study aims to develop an in-silico study of bone tissue differentiation in
diverse scaffold designs using fluid-structure interaction models. The relation between
scaffold strain deformation and fluid mechanical stimuli developed at the cell
microscopic level are analysed. The optimal configuration that leads to cell differentiation
in order to restore a bone lesion is chosen. To accomplish this, on the one hand,
computational solid mechanics and computational fluid transient states models were
implemented for all the scaffolds with steady-state and transient state inputs. On the other
hand, fluid-structure interaction models were performed considering four scenarios.
Finally, cell differentiation studies considering the octahedral shear strain and fluid shear
stress have been compared.
It has been found that high porous scaffolds with low transient state compression and
velocity resulted in an increment in bone tissue phenotype. Moreover, it has been
established that computational models not presenting interaction between solid and fluid
phases can lead to overestimating bone tissue differentiation. For this reason, it is
concluded that fluid-structure models are capable of mimicking and evaluating both
transient state mechanical stimulations closest to reality.
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