Open Access
EDITORIAL
Open Access
ARTICLE
G. Mattei1,2, A. Tirella1,2, A. Ahluwalia1,2
CMES-Computer Modeling in Engineering & Sciences, Vol.87, No.6, pp. 483-504, 2012, DOI:10.3970/cmes.2012.087.483
Abstract Biological function is intricately linked with structure. Many biological structures are characterised by functional spatially distributed gradients in which each layer has one or more specific functions to perform. Reproducing such structures is challenging, and usually an experimental trial-and-error approach is used. In this paper we investigate how the gravitational sedimentation of discrete solid particles (secondary phase) within a primary fluid phase with a time-varying dynamic viscosity can be used for the realisation of stable and reproducible continuous functionally graded materials (FGMs). Computational models were used to simulate the distribution of a particle phase in a fluid domain. Firstly a… More >
Open Access
ARTICLE
K.W. Luczynski1, A. Dejaco1, O. Lahayne1, J. Jaroszewicz2, W.Swieszkowski2, C. Hellmich1
CMES-Computer Modeling in Engineering & Sciences, Vol.87, No.6, pp. 505-529, 2012, DOI:10.3970/cmes.2012.087.505
Abstract A 71 volume-% macroporous tissue engineering scaffold made of poly-l-lactide (PLLA) with 10 mass-% of pseudo-spherical tri-calcium phosphate (TCP) inclusions (exhibiting diameters in the range of several nanometers) was microCT-scanned. The corresponding stack of images was converted into regular Finite Element (FE) models consisting of around 100,000 to 1,000,000 finite elements. Therefore, the attenuation-related, voxel-specific grey values were converted into TCP-contents, and the latter, together with nanoindentation tests,entered a homogenization scheme of the Mori-Tanaka type, as to deliver voxel-specific (and hence, finite element-specific) elastic properties. These FE models were uniaxially loaded, giving access to the macroscopic Young's modulus of the… More >
Open Access
ARTICLE
R. Khanna1,2, D. R. Katti1, K. S. Katti1
CMES-Computer Modeling in Engineering & Sciences, Vol.87, No.6, pp. 530-556, 2012, DOI:10.3970/cmes.2012.087.530
Abstract Here we report a new in situ nanoindentation technique developed to evaluate the composite mechanical behavior of cell-biomaterial construct under physiological conditions over the time scale of bone nodule generation. Using this technique, mechanical behavior of osteoblast cell-substrate interfaces on tissue engineered materials (chitosan-polygalacturonic acid-nanohydroxyapatite (CPH) films) is investigated. Mechanical behavior of cells in the elastic regime over the time scale of cell adhesion (1 day), proliferation (4 days), development (8 days) and maturation (22 days) of bone nodules is evaluated. Our results indicate that the elastic properties of flat cells are higher (indicating stiffer response, after 4 days, as… More >
Open Access
ARTICLE
MC. Ho Ba Tho1, PE Mazeran2, K El Kirat1, S.F. Bensamoun1
CMES-Computer Modeling in Engineering & Sciences, Vol.87, No.6, pp. 557-578, 2012, DOI:10.3970/cmes.2012.087.557
Abstract Mechanical properties of cortical human bone have been investigated for more than four decades. Numerous experimental investigations on bone characterization were performed ; mechanical, vibrational, acoustical testing and morphological, physico-chemical investigations. Due to the techniques, different levels of investigation were performed and subsequently quantitative parameters are concerning different level of structure of bone (organ, tissue,... ). According to our knowledge, few investigations were performed simultaneously on mechanical, morphological and physico-chemical properties of bone. The objectives of the present study were to investigate the influence of multiscale structural characteristics of the bone tissue on its mechanical behavior and to provide some… More >