Time-dependent mechanical properties of rat femoral cortical bone by nanoindentation: An age-related study

2014 ◽  
Vol 29 (10) ◽  
pp. 1135-1143 ◽  
Author(s):  
Sebastián Jaramillo Isaza ◽  
Pierre-Emmanuel Mazeran ◽  
Karim El Kirat ◽  
Marie-Christine Ho Ba Tho
Keyword(s):  
Mechanical Properties ◽  
Cortical Bone ◽  
Time Dependent ◽  
Age Related ◽  
Image Position

Abstract

NANOINDENTATION AND ASH CONTENT STUDY OF AGE DEPENDENT CHANGES IN PORCINE CORTICAL BONE

2015 ◽  
Vol 15 (05) ◽  
pp. 1550074 ◽  
Author(s):  
MICHAEL CHITTENDEN ◽  
AHMAD RAEISI NAJAFI ◽  
JUN LI ◽  
IWONA JASIUK
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Cortical Bone ◽  
Age Groups ◽  
Structure Property ◽  
Micro Computed Tomography ◽  
Mineral Contents ◽  
Age Related ◽  
Age Dependent ◽  
Composition Structure

Composition-structure-property relations of bone provide fundamental understanding of bone quality. The objective of this paper was to investigate age dependent changes in the composition, structure and mechanical properties of porcine femoral cortical bone at mid-diaphysis region from six age groups (1, 3.5, 6, 12, 30, 48 months). This study was motivated by the fact that limited data is available in the literature on young porcine cortical bone. Nanoindentation technique with Berkovich fluid cell tip was employed to measure the elastic modulus and hardness. Individual lamellae were indented in the longitudinal direction of bone in different microstructural components (osteonal, interstitial and plexiform bone). A grid of indentations was also made on one bone sample to obtain spatial variations in the elastic modulus and hardness. Ash and water content tests were performed to measure water, organic and mineral contents of bone as a function of age. Finally, high resolution micro-computed tomography was used to measure porosity and visualize three-dimensional void structures. We found that the elastic modulus and hardness of bone increased with age but at different rates in each microstructural component. The mineral content increased correspondingly with age while the porosity decreased. The obtained structure, composition, and mechanical properties data give new insights on the age related changes in young cortical bone and can serve as inputs for and validation of multiscale models of bone.

HETEROGENEITY OF TIME-DEPENDENT MECHANICAL PROPERTIES OF HUMAN CORTICAL BONE AT THE MICRO SCALE

2015 ◽  
Vol 18 (04) ◽  
pp. 1550017 ◽  
Author(s):  
Sebastián Jaramillo-Isaza ◽  
Pierre-Emmanuel Mazeran ◽  
Karim El-Kirat ◽  
Marie-Christine Ho Ba Tho
Keyword(s):  
Mechanical Properties ◽  
Cortical Bone ◽  
Mineral Content ◽  
Mechanical Response ◽  
Extreme Values ◽  
Numerical Models ◽  
Time Dependent ◽  
Femoral Diaphysis ◽  
Interstitial Tissue ◽  
Micro Scale

Background: Remodeling process affects the mineral content of osteons and imparts heterogeneity through secondary mineralization; the aim of the present study is to assess the elastic and plastic time-dependent mechanical properties of osteons reflecting different mineral content as well as interstitial tissue of human femoral cortical bone by nanoindentation. Methods: Four trapezoiform blocks approximately 3[Formula: see text]mm thick were cut from the distal end of different human femoral diaphysis. Osteons with different apparent mineral degrees were classified by means of gray levels imaging using Environmental Scanning Electron Microscopy (ESEM). Nanoindentation tests were performed in the longitudinal direction of the bone axis using a four-stage protocol (load-hold-unload-hold) and the experimental curves were fitted by a mechanical model allowing the determination of the time-dependent mechanical properties. Results: Apparent low mineral content impact negatively the mechanical response of bone material at the micro-scale. Mechanical response varies among osteons exhibiting different mineral degrees. The values of the apparent elastic modulus double when the strain rate is analyzed at the extreme values ([Formula: see text] and infinity) whatever the bone component. Conclusions: These results evidence the mechanical heterogeneity of bone microstructure due to remodeling process. The quantification of the time-dependent mechanical properties could be useful to improve numerical models of bone behavior and provide new insights to build up original biomimetic materials.

Quantification of Age-Related Tissue-Level Failure Strains of Rat Femoral Cortical Bones Using an Approach Combining Macrocompressive Test and Microfinite Element Analysis

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Ruoxun Fan ◽  
He Gong ◽  
Rui Zhang ◽  
Jiazi Gao ◽  
Zhengbin Jia ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cortical Bone ◽  
Failure Strain ◽  
Skeletal Maturity ◽  
Tissue Level ◽  
Male Rat ◽  
Bone Mechanical Properties ◽  
Age Related ◽  
Different Ages ◽  
Different Levels

Bone mechanical properties vary with age; meanwhile, a close relationship exists among bone mechanical properties at different levels. Therefore, conducting multilevel analyses for bone structures with different ages are necessary to elucidate the effects of aging on bone mechanical properties at different levels. In this study, an approach that combined microfinite element (micro-FE) analysis and macrocompressive test was established to simulate the failure of male rat femoral cortical bone. Micro-FE analyses were primarily performed for rat cortical bones with different ages to simulate their failure processes under compressive load. Tissue-level failure strains in tension and compression of these cortical bones were then back-calculated by fitting the experimental stress–strain curves. Thus, tissue-level failure strains of rat femoral cortical bones with different ages were quantified. The tissue-level failure strain exhibited a biphasic behavior with age: in the period of skeletal maturity (1–7 months of age), the failure strain gradually increased; when the rat exceeded 7 months of age, the failure strain sharply decreased. In the period of skeletal maturity, both the macro- and tissue-levels mechanical properties showed a large promotion. In the period of skeletal aging (9–15 months of age), the tissue-level mechanical properties sharply deteriorated; however, the macromechanical properties only slightly deteriorated. The age-related changes in tissue-level failure strain were revealed through the analysis of male rat femoral cortical bones with different ages, which provided a theoretical basis to understand the relationship between rat cortical bone mechanical properties at macro- and tissue-levels and decrease of bone strength with age.

scholarly journals Age related extracellular matrix and interstitial cell phenotype in pulmonary valves

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shaohua Wu ◽  
Vikas Kumar ◽  
Peng Xiao ◽  
Mitchell Kuss ◽  
Jung Yul Lim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Extracellular Matrix ◽  
Heart Valve ◽  
Cell Phenotype ◽  
Primary Concern ◽  
Ross Operation ◽  
Age Related ◽  
Cardiovascular Morbidity And Mortality ◽  
Extracellular Matrix Components ◽  
Matrix Components

AbstractHeart valve disease is a common manifestation of cardiovascular disease and is a significant cause of cardiovascular morbidity and mortality worldwide. The pulmonary valve (PV) is of primary concern because of its involvement in common congenital heart defects, and the PV is usually the site for prosthetic replacement following a Ross operation. Although effects of age on valve matrix components and mechanical properties for aortic and mitral valves have been studied, very little is known about the age-related alterations that occur in the PV. In this study, we isolated PV leaflets from porcine hearts in different age groups (~ 4–6 months, denoted as young versus ~ 2 years, denoted as adult) and studied the effects of age on PV leaflet thickness, extracellular matrix components, and mechanical properties. We also conducted proteomics and RNA sequencing to investigate the global changes of PV leaflets and passage zero PV interstitial cells in their protein and gene levels. We found that the size, thickness, elastic modulus, and ultimate stress in both the radial and circumferential directions and the collagen of PV leaflets increased from young to adult age, while the ultimate strain and amount of glycosaminoglycans decreased when age increased. Young and adult PV had both similar and distinct protein and gene expression patterns that are related to their inherent physiological properties. These findings are important for us to better understand the physiological microenvironments of PV leaflet and valve cells for correctively engineering age-specific heart valve tissues.

Ageing Changes in the Tensile Properties of Tendons: Influence of Collagen Fibril Volume Fraction

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
K. L. Goh ◽  
D. F. Holmes ◽  
H.-Y. Lu ◽  
S. Richardson ◽  
K. E. Kadler ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Collagen Fibril ◽  
Volume Fraction ◽  
Area Fraction ◽  
Sectional Area ◽  
Cross Sectional ◽  
P Values ◽  
Age Related ◽  
Fibril Diameter ◽  
Age Related Changes

Connective tissues are biological composites comprising of collagen fibrils embedded in (and reinforcing) the hydrated proteoglycan-rich (PG) gel within the extracellular matrices (ECMs). Age-related changes to the mechanical properties of tissues are often associated with changes to the structure of the ECM, namely, fibril diameter. However, quantitative attempts to correlate fibril diameter to mechanical properties have yielded inconclusive evidence. Here, we described a novel approach that was based on the rule of mixtures for fiber composites to evaluate the dependence of age-related changes in tendon tensile strength (σ) and stiffness (E) on the collagen fibril cross-sectional area fraction (ρ), which is related to the fibril volume fraction. Tail tendons from C57BL6 mice from age groups 1.6–35.3months old were stretched to failure to determine σ and E. Parallel measurements of ρ as a function of age were made using transmission electron microscopy. Mathematical models (rule of mixtures) of fibrils reinforcing a PG gel in tendons were used to investigate the influence of ρ on ageing changes in σ and E. The magnitudes of σ, E, and ρ increased rapidly from 1.6monthsto4.0months (P-values <0.05) before reaching a constant (age independent) from 4.0monthsto29.0months (P-values >0.05); this trend continued for E and ρ (P-values >0.05) from 29.0monthsto35.3months, but not for σ, which decreased gradually (P-values <0.05). Linear regression analysis revealed that age-related changes in σ and E correlated positively to ρ (P-values <0.05). Collagen fibril cross-sectional area fraction ρ is a significant predictor of ageing changes in σ and E in the tail tendons of C57BL6 mice.

Effects of alumina (Al2O3) addition on the cell structure and mechanical properties of 6061 foams

2013 ◽  
Vol 28 (17) ◽  
pp. 2509-2519 ◽  
Author(s):  
Nazim Mahmutyazicioglu ◽  
Onder Albayrak ◽  
Mehmet Ipekoglu ◽  
Sabri Altintas
Keyword(s):  
Mechanical Properties ◽  
Cell Structure ◽  
Al2o3 Addition ◽  
Image Position

Abstract

Orientation and age-related dependence of the fracture toughness of cortical bone

1985 ◽  
Vol 18 (7) ◽  
pp. 521-522 ◽  
Author(s):  
W. Bonfield ◽  
J.C. Behiri ◽  
B. Cullen
Keyword(s):  
Fracture Toughness ◽  
Cortical Bone ◽  
Age Related
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