Raman Spectroscopic Analysis to Detect Reduced Bone Quality after Sciatic Neurectomy in Mice

Abstract

Bone mineral density (BMD) is a commonly used diagnostic indicator for bone fracture risk in osteoporosis. Along with low BMD, bone fragility accounts for reduced bone quality in addition to low BMD, but there is no diagnostic method to directly assess the bone quality. In this study, we investigated changes in bone quality using the Raman spectroscopic technique. Sciatic neurectomy (NX) was performed in male C57/BL6J mice (NX group) as a model of disuse osteoporosis, and sham surgery was used as an experimental control (Sham group). Eight months after surgery, we acquired Raman spectral data from the anterior cortical surface of the proximal tibia. We also performed a BMD measurement and micro-CT measurement to investigate the pathogenesis of osteoporosis. Quantitative analysis based on the Raman peak intensities showed that the carbonate/phosphate ratio and the mineral/matrix ratio were significantly higher in the NX group than in the Sham group. There was direct evidence of alterations in the mineral content associated with mechanical properties of bone. To fully understand the spectral changes, we performed principal component analysis of the spectral dataset, focusing on the matrix content. In conclusion, Raman spectroscopy provides reliable information on chemical changes in both mineral and matrix contents, and it also identifies possible mechanisms of disuse osteoporosis.

Breast cancer–secreted factors perturb murine bone growth in regions prone to metastasis

“…S8F). Both spectral regions are characteristic of the organic matrix ( 31 ), and this ratio has previously been used to estimate the amount of total organic molecule content relative to matrix proteins ( 32 ). Modified values of the CH 2 -wag band have also been observed in some types of malignant tissues ( 33 ).…”

Electroacupuncture ameliorates intestinal inflammation by activating α7nAChR-mediated JAK2/STAT3 signaling pathway in postoperative ileus

“…The skin incision was made posterior to the femoral trochanteric region. The sciatic nerve was exposed and a 1-cm-long segment was resected before the EA treatment, as described in Ishimaru et al 20 . In the sham group mice were anesthetized and incised in the same manner as the sciatic neurectomy group but without sciatic neurectomy.…”

Comparative analysis of bovine serum albumin adsorption onto octacalcium phosphate crystals prepared using different methods

“…In both reference spectra, the peaks attributed to amide III of β-sheet/random coils, α-helix, α-fibrous/γ(CH 2), and α-helix were detected at 1,230 44) , 1,264 44) , 1,312 45,46) , and 1,340 cm −1 44) , respectively. In addition, the peaks assigned to δ(C-C), amide II, and amino acids (tyrosine and phenylalanine) were observed at 1,450 [44][45][46][47] and 1,605 cm −1 45,46) , respectively. In the region of amide I, the peaks attributed to α-helix and random coils were observed at 1,650 and 1,677 cm −1 45,46) , respectively.…”

“…4-6). The peak intensity ratios for 1,264 44) and 1,312 cm −1 45) (α-helix and α-fibrous/γ(CH2)) or for 1,605 and 1,650 cm −1 (amino acid and α-helix) 45) (Table 3) indicated that BSA may have actually adsorbed onto both c-OCP and w-OCP. Although the BSA adsorption sites on c-OCP and w-OCP surfaces are unclear, the mechanism may involve some types of adsorption [56][57][58] .…”