title: Numerical Study of Granular Scaffold Efficiency to Convert Fluid Flow into Mechanical Stimulation in Bone Tissue Engineering.
abstract: Controlling the mechanical environment in bioreactors represents a key element in the reactors' optimization. Positive effects of fluid flow in three-dimensional bioreactors have been observed, but local stresses at cell scale remain unknown. These effects led to the development of numerical tools to assess the micromechanical environment of cells in bioreactors. Recently, new possible scaffold geometry has emerged: granular packings. In the present study, the primary goal was to compare the efficiency of such a scaffold to the other ones from literature in terms of wall shear stress levels and distributions. To that aim, three different types of granular packings were generated through discrete element method, and computational fluid dynamics was used to simulate the flow within these packings. Shear stress levels and distributions were determined. A linear relationship between shear stress and inlet velocity was observed, and its slope was similar to published data. The distributions of normalized stress were independent of the inlet velocity and were highly comparable to those of widely used porous scaffolds. Granular packings present similar features to more classical porous scaffolds and have the advantage of being easy to manipulate and seed. The methods of this work are generalizable to the study of other granular packing configurations.
authors: 1 Laboratoire de Tribologie et Dynamique des Systèmes (LTDS, UMR CNRS 5513) , Ecole Centrale de Lyon, Ecully Cedex, France .
authors: Magali
authors: M
authors: Cruel
authors: 2 Laboratory of Bioengineering and Biomechanics for Bone and Articulations (B2OA, UMR CNRS 7052), University of Paris 7 , PRES Paris Cité, Paris, France .
authors: Morad
authors: M
authors: Bensidhoum
authors: 1 Laboratoire de Tribologie et Dynamique des Systèmes (LTDS, UMR CNRS 5513) , Ecole Centrale de Lyon, Ecully Cedex, France .
authors: Cécile
authors: C
authors: Nouguier-Lehon
authors: 1 Laboratoire de Tribologie et Dynamique des Systèmes (LTDS, UMR CNRS 5513) , Ecole Centrale de Lyon, Ecully Cedex, France .
authors: Olivier
authors: O
authors: Dessombz
authors: 2 Laboratory of Bioengineering and Biomechanics for Bone and Articulations (B2OA, UMR CNRS 7052), University of Paris 7 , PRES Paris Cité, Paris, France .
authors: Pierre
authors: P
authors: Becquart
authors: 2 Laboratory of Bioengineering and Biomechanics for Bone and Articulations (B2OA, UMR CNRS 7052), University of Paris 7 , PRES Paris Cité, Paris, France .
authors: Hervé
authors: H
authors: Petite
authors: 1 Laboratoire de Tribologie et Dynamique des Systèmes (LTDS, UMR CNRS 5513) , Ecole Centrale de Lyon, Ecully Cedex, France .
authors: Thierry
authors: T
authors: Hoc
mesh_terms: D001842:Bone and Bones / Q000502:physiology*; D057446:Hydrodynamics; D009716:Numerical Analysis, Computer-Assisted; D016062:Porosity; D011336:Probability; D033081:Shear Strength; D013314:Stress, Mechanical; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*