Mechanical and flow characterization of Sponceram® carriers: Evaluation by homogenization theory and experimental validation

Abstract

The experimental evidence of the dependence of cell proliferation and differentiation in vitro on the mechanical environment aims to the need of characterization of porous scaffolds in terms of mechanical and flow properties. In this sense, the Young's modulus and intrinsic permeability for three types of Sponceram(R) cell carriers developed for in-vitro applications are here analyzed. Young's modulus and ultimate compression stress were obtained by performing a two-plates compression test carried out in a universal microtester machine Instron(R) for several representative samples of each specimen. A permeability test was also implemented to correlate flow rate and pressure gradient in the linear range. Furthermore, porosity and specific surface were obtained through micro-CTs of the scaffold microstructure. These experimental data were compared with those obtained numerically by homogenization for several representative volume elements (RVEs) of the scaffolds microstructure. The good agreement found between numerical and experimental results let us consider that the use of numerical techniques is an attractive tool for the analysis of complex scaffold microstructures. Moreover, Sponceram(R) carriers are shown to have very appropriate properties as bone bioscaffolds which let us recommending further clinical and numerical research on these specific materials.

Permeability analysis of scaffolds for bone tissue engineering

“…Moreover, the dependence of permeability on pore radius and cell size is also noted in works that use the asymptotic homogenization theory to determine an equivalent permeability coefficient, homogenizing the Stokes equations (Terada et al, 1998;Sanz-Herrera et al, 2008). In this approach, the homogenized coefficient is determined by solving the fluid flow problem through the void domain (void channels) of the unit cell.…”

Bioactive glass and glass-ceramic scaffolds for bone tissue engineering

“…To our knowledge, there are only a few studies on the permeability assessment/evaluation of porous bioceramic scaffolds including both numerical modeling [147] and experimental determination of permeability constants [95,145,148,149]. In a recent study on bioactive glass-ceramic scaffolds confirming that the fabricated scaffolds had transport properties as well as pore structure close to trabecular bone.…”

A mathematical approach to bone tissue engineering

“…For this purpose, homogenization theory was extensively applied in their studies. Additionally, mechanical properties and permeability were homogenized over a representative element of a bioceramic scaffold microstructure (Sanz-Herrera et al 2008c). The obtained results were corroborated by an experimental set-up showing the potential of numerical tools for the characterization of scaffold properties.…”