Publication Details

Category Text Publication
Reference Category Journals
DOI 10.22203/eCM.v029a09
Title (Primary) Postnatal changes to the mechanical properties of articular cartilage are driven by the evolution of its collagen network
Author Gannon, A.R.; Nagel, T.; Bell, A.P.; Avery, N.C.; Kelly, D.J.
Journal European Cells & Materials
Year 2015
Department ENVINF
Volume 29
Page From 105
Page To 123
Language englisch
Keywords Articular cartilage; collagen; Young’s modulus; digital image correlation; helium ion microscopy; maturation; structure-function relations
UFZ wide themes RU5;
Abstract While it is well established that the composition and organisation of articular cartilage dramatically change during skeletal maturation, relatively little is known about how this impacts the mechanical properties of the tissue. In this study, digital image correlation was first used to quantify spatial deformation within mechanically compressed skeletally immature (4 and 8 week old) and mature (1 and 3 year old) porcine articular cartilage. The compressive modulus of the immature tissue was relatively homogeneous, while the stiffness of mature articular cartilage dramatically increased with depth from the articular surface. Other, well documented, biomechanical characteristics of the tissue also emerged with skeletal maturity, such as strain-softening and a depth-dependent Poisson’s ratio. The most significant changes that occurred with age were in the deep zone of the tissue, where an order of magnitude increase in compressive modulus (from 0.97 MPa to 9.4 MPa for low applied strains) was observed from 4 weeks postnatal to skeletal maturity. These temporal increases in compressive stiffness occurred despite a decrease in tissue sulphated glycosaminoglycan content, but were accompanied by increases in tissue collagen content. Furthermore, helium ion microscopy revealed dramatic changes in collagen fibril alignment through the depth of the tissue with skeletal maturity, as well as a fivefold increase in fibril diameter with age. Finally, computational modelling was used to demonstrate how both collagen network reorganisation and collagen stiffening play a key role in determining the final compressive mechanical properties of the tissue. Together these findings provide a unique insight into evolving structure-function relations in articular cartilage.
Persistent UFZ Identifier
Gannon, A.R., Nagel, T., Bell, A.P., Avery, N.C., Kelly, D.J. (2015):
Postnatal changes to the mechanical properties of articular cartilage are driven by the evolution of its collagen network
Eur. Cells Mater. 29 , 105 - 123