Calcified Tissue International ( IF 4.2 ) Pub Date : 2021-03-12 , DOI: 10.1007/s00223-021-00825-4 Erik A Taylor 1 , Cassidy J Mileti 2 , Sandhya Ganesan 3 , Joo Ho Kim 3 , Eve Donnelly 3, 4
Bone mineral carbonate content assessed by vibrational spectroscopy relates to fracture incidence, and mineral maturity/ crystallinity (MMC) relates to tissue age. As FT-IR and Raman spectroscopy become more widely used to characterize the chemical composition of bone in pre-clinical and translational studies, their bone mineral outcomes require improved validation to inform interpretation of spectroscopic data. In this study, our objectives were (1) to relate Raman and FT-IR carbonate:phosphate ratios calculated through direct integration of peaks to gold-standard analytical measures of carbonate content and underlying subband ratios; (2) to relate Raman and FT-IR MMC measures to gold-standard analytical measures of crystal size in chemical standards and native bone powders. Raman and FT-IR direct integration carbonate:phosphate ratios increased with carbonate content (Raman: p < 0.01, R2 = 0.87; FT-IR: p < 0.01, R2 = 0.96) and Raman was more sensitive to carbonate content than the FT-IR (Raman slope + 95% vs FT-IR slope, p < 0.01). MMC increased with crystal size for both Raman and FT-IR (Raman: p < 0.01, R2 = 0.76; FT-IR p < 0.01, R2 = 0.73) and FT-IR was more sensitive to crystal size than Raman (c-axis length: slope FT-IR MMC + 111% vs Raman MMC, p < 0.01). Additionally, FT-IR but not Raman spectroscopy detected differences in the relationship between MMC and crystal size of carbonated hydroxyapatite (CHA) vs poorly crystalline hydroxyapatites (HA) (slope CHA + 87% vs HA, p < 0.01). Combined, these results contribute to the ability of future studies to elucidate the relationships between carbonate content and fracture and provide insight to the strengths and limitations of FT-IR and Raman spectroscopy of native bone mineral.
中文翻译:
用于 FT-IR 和拉曼光谱成像的骨矿物碳酸盐含量和矿物成熟度/结晶度的测量与碳酸盐取代羟基磷灰石的物理化学性质有差异
通过振动光谱评估的骨矿物碳酸盐含量与骨折发生率有关,矿物成熟度/结晶度 (MMC) 与组织年龄有关。随着 FT-IR 和拉曼光谱在临床前和转化研究中更广泛地用于表征骨的化学成分,它们的骨矿物质结果需要改进验证以告知光谱数据的解释。在这项研究中,我们的目标是 (1) 将拉曼和 FT-IR 碳酸盐:磷酸盐比率通过直接积分峰与碳酸盐含量和潜在子带比率的黄金标准分析测量值联系起来;(2) 将拉曼和 FT-IR MMC 测量与化学标准和天然骨粉中晶体尺寸的金标准分析测量联系起来。拉曼和 FT-IR 直接积分碳酸盐:2 = 0.87;FT-IR:p < 0.01,R 2 = 0.96),拉曼对碳酸盐含量比 FT-IR 更敏感(拉曼斜率 + 95% 对 FT-IR 斜率,p < 0.01)。MMC 随拉曼和 FT-IR 的晶体尺寸增加(拉曼:p < 0.01,R 2 = 0.76;FT-IR p < 0.01,R 2 = 0.73) 并且 FT-IR 对晶体尺寸比拉曼更敏感(c 轴长度:斜率 FT-IR MMC + 111% 与拉曼 MMC,p < 0.01)。此外,FT-IR 而非拉曼光谱检测到 MMC 与碳酸羟基磷灰石 (CHA) 与结晶度差的羟基磷灰石 (HA) 的晶体大小之间关系的差异(斜率 CHA + 87% 与 HA,p < 0.01)。综合起来,这些结果有助于未来研究阐明碳酸盐含量与断裂之间的关系,并提供对 FT-IR 和天然骨矿物质拉曼光谱的优势和局限性的洞察力。