Raman Spectroscopic Studies of Bone Biomechanical Function and Developmentin Animal Models.

[摘要] Raman spectroscopy is a versatile technique for studying multiple aspects of bone health.Raman bands are sensitive to the composition and structural orientation of the material and to external mechanical forces.Through examination of bone tissue from various animal models, this dissertation demonstrates the ability of Raman spectroscopy to advance knowledge of bone biomechanical function and normal bone development.Stress was measured in an equine model for the early stages of bone fracture by analyzing band shifts in phosphate ν1, the most prominent mineral band in bone.Stresses were significantly higher in strained and failed regions than in control regions, and the pattern of stresses as calculated with Raman imaging was in agreement with the predicted stresses from a linear finite element analysis model of the fracture specimen.In an equine model for an extreme athlete, the third metacarpal bone from a racehorse was found to have an increased mineral to matrix ratio, an indicator of tissue mineralization, compared to a specimen from a nonathletic horse.Raman spectroscopy was also applied to evaluate bone tissue from genetically modified mice in which the Sprouty2 gene, a gene which regulates normal bone development, was deleted.Based on observed differences in the collagen cross link and mineral to matrix band ratios, Spry2 appears to regulate cross link formation and accrual of mineral during normal bone development.Another genetically modified mouse examined was the Brittle mouse, a model for osteogenesis imperfecta type IV.In this model, an amino acid point substitution prevents proper folding of the collagen triple helix. Polarized Raman spectroscopy was used to assess the orientations of bone mineral and collagen fibrils in Brittle and wild-type mice.Surprisingly, no significant differences between genotypes were detected.Finally, improvements to ex vivo, through the skin bone measurements on animal tissue are presented, along with an experimental study detailing the improvements to fiber spectra obtained by applying software corrections to coupling errors that arise in collection with fiber bundles.

[发布机构] University of Michigan

[效力级别] Bone

[关键词] Raman Spectroscopy;Bone;Osteogenesis Imperfecta;Molecular Orientation of Bone Mineral and Collagen;Polarized Raman Spectroscopy;Chemistry;Science;Chemistry