Abstract
Bone is a composite material composed of mineral particles (mainly Hydroxyapatite: HAp) and organic matrix (mostly type I collagen) in a microscopic scale. Macroscopic mechanical properties of bone are dependent on the structure and mechanical properties of these microscopic constituents. Raman spectroscopy is known to be useful tool for the analysis of material at the molecular and crystal level by using the unique frequency (Raman shift) depends on the molecular bonds. The aim of this study is to measure the mechanical behaviors of mineral and organic phases by using Raman spectroscopy, and to investigate the effects of its anisotropy and aging of bone tissues. As the results, the Raman shift of v1PO_4^<3-> and Amide I decreased linearly with the tensile loading. Then the ratio of Raman shift change to applied stress (Δv/σ) of v_1PO_4^<3-> and that of Amide I were highest during loading at bone axial direction. In addition, the changes in the Raman shift showed a similar tendency at the age of 23 months and 9 years old, the change of the age of 9 years old was smaller. From the results, the mechanical response of mineral and organic phase in bone tissue could be measured by using Raman spectroscopy. And it could be indicated that Raman responses of bone tissue were dependent to anisotropic properties and degree of aging.
