This study demonstrates a novel approach to characterizing hydrated bone's viscoelastic behavior at lamellar length scales using dynamic indentation techniques. We studied the submicron-level viscoelastic response of bone tissue from two different inbred mouse strains, A/J and B6, with known differences in whole bone and tissue-level mechanical properties. Our results show that bone having a higher collagen content or a lower mineral-to-matrix ratio demonstrates a trend towards a larger viscoelastic response. When normalized for anatomical location relative to biological growth patterns in the antero-medial (AM) cortex, bone tissue from B6 femora, known to have a lower mineral-to-matrix ratio, is shown to exhibit a significantly higher viscoelastic response compared to A/J tissue. Newer bone regions with a higher collagen content (closer to the endosteal edge of the AM cortex) showed a trend towards a larger viscoelastic response. Our study demonstrates the feasibility of this technique for analyzing local composition-property relationships in bone. Further, this technique of viscoelastic nanoindentation mapping of the bone surface at these submicron length scales is shown to be highly advantageous in studying subsurface features, such as porosity, of wet hydrated biological specimens, which are difficult to identify using other methods.
|Number of pages||10|
|Journal||Journal of the Mechanical Behavior of Biomedical Materials|
|Early online date||16 Sep 2010|
|Publication status||Published - Jan 2011|
Bibliographical noteNOTICE: this is the author’s version of a work that was accepted for publication in Journal of the Mechanical Behavior of Biomedical Materials. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Pathak, S, Kalidindi, S, Swadener, G, Courtland, H, Jepsen, K & Goldman, H, 'Measuring the dynamic mechanical response of hydrated mouse bone by nanoindentation', Journal of the Mechanical Behavior of Biomedical Materials, vol 4, no. 1, pp. 34-43, (2011). DOI http://dx.doi.org/10.1016/j.jmbbm.2010.09.002