Age- and site-associated biomechanical weakening of human articular cartilage of the femoral condyle

Abstract

Many of these age-associated differences are identical to those regarded as pathological features of cartilage degeneration in early osteoarthritis. These findings provide evidence for the roles of mechanical wear, cell death, and enzymatic degradation in mediating the progression through successive and distinguishable stages of early cartilage deterioration.

Multiscale cartilage biomechanics: technical challenges in realizing a high-throughput modelling and simulation workflow

“…It is anticipated that this framework will be used to understand cartilage and chondrocyte mechanics during ageing. Ageing manifests anatomical and mechanical changes at multiple scales [13,16,19,58], which in turn perturb the mechanical environment and therefore associated biological responses to mechanical stimuli. Similarly, this modelling and simulation workflow will likely be a significant toolset to evaluate the complicated mechanical state of the tissue and cells during the onset and progression of osteoarthritis.…”

“…Regional cartilage anatomy (curvature, thickness), stiffness, zonal properties, i.e. delineation of superficial, transitional and deep layers, and fibrillar architecture [13][14][15][16], and chondrocyte organization, shape, size [17,18] and mechanical properties [19] all vary largely among species and between individuals and can be altered by injury or disease. A high-throughput modelling and simulation framework seeks to provide the ability to represent such variations and conduct individualized analysis to assess this multiscale mechanical system under various loading conditions, which can be used for understanding trauma risk, for evaluating the protective performance of interventions, and for diagnosis and prognosis through the use of biomechanical markers.…”

Cartilage Matrix Formation by Bovine Mesenchymal Stem Cells in Three-dimensional Culture Is Age-dependent

“…In human articular cartilage, Temple and colleagues showed no agerelated biochemical changes and a decrease in equilibrium modulus for only the 60 + age group; however, the youngest (21-39 years) age group was already skeletally mature [48]. Studying younger donors, Kempson found increasing tensile properties of human articular cartilage until the third decade and suggested refinement of the collagenous network for 30 years [26].…”

Compaction Enhances Extracellular Matrix Content and Mechanical Properties of Tissue-Engineered Cartilaginous Constructs

“…Based on the measured thickness of compacted constructs without ARC, the final cell density is *3-4 · 10 6 cells/mL, which is *1/4-1/2 of the cell density in native human adult cartilage. 7 As the present study involved short-term culture of constructs containing immature chondrocytes, substantial studies in vitro with longer-term culture and use of different cell types and densities, as well as in vivo studies, are needed to further elucidate the effect of compaction and addition of native ECM components in tissue-engineered constructs on cell viability, water content, and matrix deposition by the indwelling cells. With longer-term studies, cell survival and fates (viability, proliferation, differentiation, and migration) may become more challenging to assess.…”

“…5 However, many cell-based tissue-engineered constructs for articular cartilage are mechanically soft and have an imbalance between its ECM components. In normal cartilage, the COL content is typically *2-10 times higher than sGAG content in cartilage ranging in maturity from immature fetal bovine to adult human cartilage, respectively (Table 1), 6,7 whereas the typical ratio of COL:sGAG in engineered cartilage is 1:1 or less, even after prolonged culture. [8][9][10] After culture, cartilaginous constructs may attain a PG content that approaches physiological levels, although its COL content is substantially below that of native cartilage.…”