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Publication Citation: Nanomechanical mapping of the osteochondral interface with contact resonance force microscopy and nanoindentation

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Author(s): Sara E. Campbell; Virginia L. Ferguson; Donna C. Hurley;
Title: Nanomechanical mapping of the osteochondral interface with contact resonance force microscopy and nanoindentation
Published: August 06, 2012
Abstract: The bone-cartilage, or osteochondral, interface resists remarkably high shear stresses and rarely fails, yet its mechanical characteristics are largely unknown. A complete understanding of this hierarchical system requires mechanical-property information at both the length scale of the interface and that of the connecting tissues. Here, we combined nanoindentation and atomic force microscopy (AFM) methods to investigate the multiscale mechanical properties across the osteochondral interface. The indentation modulus M ranged from that of the subchondral bone [M = (22.8 ± 1.8) GPa] to that of hyaline articular cartilage [M = (5.7 ± 1.0) GPa] across a narrow transition region <5 µm wide. Contact resonance force microscopy (CR-FM), which measures the frequency and quality factor of the AFM cantilever‰s vibrational resonance in contact mode, was used to determine the relative storage modulus M' and loss tangent. With better spatial resolution than nanoindentation, CR-FM measurements indicated an even narrower (2.3 ± 1.2 µm) interface. Furthermore, CR-FM revealed a 24 % increase in the viscoelastic loss tangent from the articular calcified cartilage to the hyaline articular cartilage. Quantitative backscatter electron imaging provided complimentary measurement of mineral content and mechanical properties. Our results provide insight into the multiscale functionality of the osteochondral interface that will advance understanding of disease states such as osteoarthritis and aid in the development of biomimetic interfaces.
Citation: ACTA Biomaterialia
Volume: 8 (2012)
Pages: pp. 4389 - 4396
Research Areas: Electron microscopy (EM, TEM, SEM, STEM), Characterization, Atomic force microscopy (AFM), Biomaterials
PDF version: PDF Document Click here to retrieve PDF version of paper (1MB)