Quantitative mechanical/chemical imaging of bone from Dmp1 null mice

Xiaomei Yao, Lynda F. Bonewald, J. David Eick, Yong Wang

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Dentin matrix protein 1 (DMP1) is an acidic noncollagenous protein which plays an important role in mineralized tissue formation. Dmp1 null adult mice are ricketic and osteomalacic and are a model for hypophosphatemic rickets [1]. Mutation in humans results is Autosomal Recessive Hypophosphatic Rickets [1]. The degree of bone mineralization significantly contributes to bone tissue mechanical properties, but precise relationships and interactions between chemical and mechanical variables are unknown. The objective of this study was to relate the differences in chemical properties in the Dmp1 wildtype (WT) and null (KO) mouse femoral cortical bone to their mechanical properties by using FTIR imaging and Scanning Acoustic Microscopy (SAM). Interactive mechanical (elastic modulus) and chemical images (i.e., mineral/matrix ratios) were generated from the same region of bone at a lateral resolution of ∼10 um. Mechanical analysis showed that elastic modulus, 75 percentile around 7.1 GPa, was ∼60% less in Dmp1 KO than that in WT, in which elastic modulus was 75 percentile around 15.2 GPa. The mineral-to-matrix ratios in Dmp1KO (4.96±1.63) were ∼2 times lower than that in Dmp1 WT (8.65±1.14). The mineral crystallinity and collagen crosslink ratios were not significantly different between KO and WT. Conclusions: The results relate the bone elastic modulus changes in Dmp1WT and KO mice with chemical changes within a specific bone site. These measurements provide a new tool for describing the variability of bone chemical and mechanical properties.

Original languageEnglish (US)
Title of host publicationStructure-Property Relationships in Biomineralized and Biomimetic Composites
Pages187-192
Number of pages6
StatePublished - Dec 1 2009
Externally publishedYes
Event2009 MRS Spring Meeting - San Francisco, CA, United States
Duration: Apr 14 2009Apr 17 2009

Publication series

NameMaterials Research Society Symposium Proceedings
Volume1187
ISSN (Print)0272-9172

Other

Other2009 MRS Spring Meeting
CountryUnited States
CitySan Francisco, CA
Period4/14/094/17/09

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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  • Cite this

    Yao, X., Bonewald, L. F., Eick, J. D., & Wang, Y. (2009). Quantitative mechanical/chemical imaging of bone from Dmp1 null mice. In Structure-Property Relationships in Biomineralized and Biomimetic Composites (pp. 187-192). (Materials Research Society Symposium Proceedings; Vol. 1187).