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Abstract：
BACKGROUND: To perform a detailed morphological analysis of the inorganic portion of two different clinical presentations of calcium-based deposits retrieved from subjects with SSc and identify a chemical dissolution of these deposits suitable for clinical use.
METHODS: Chemical analysis using Fourier Transform IR spectroscopy (\'FTIR\'), Raman microscopy, Powder X-Ray Diffraction (\'PXRD\'), and Transmission Electron Microscopy (\'TEM\') was undertaken of two distinct types of calcinosis deposits: paste and stone. Calcinosis sample titration with ethylenediaminetetraacetic acid (\'EDTA\') assessed the concentration at which the EDTA dissolved the calcinosis deposits in vitro.
RESULTS: FTIR spectra of the samples displayed peaks characteristic of hydroxyapatite, where signals attributable to the phosphate and carbonate ions were all identified. Polymorph characterization using Raman spectra were identical to a hydroxyapatite reference while the PXRD and electron diffraction patterns conclusively identified the mineral present as hydroxyapatite. TEM analysis showed differences of morphology between the samples. Rounded particles from stone samples were up to a few micron in size, while needle-like crystals from paste samples reached up to 0.5 µm in length. Calcium phosphate deposits were effectively dissolved with 3% aqueous solutions of EDTA, in vitro. Complete dissolution of both types of deposit was achieved in approximately 30 min using a molar ratio of EDTA/HAp of ≈ 300.
CONCLUSIONS: Stone and paste calcium-based deposits both comprise hydroxyapatite, but the constituent crystals vary in size and morphology. Hydroxyapatite is the only crystalline polymorph present in the SSc-related calcinosis deposits. Hydroxyapatite can be dissolved in vitro using a dosage of EDTA considered safe for clinical application. Further research is required to establish the optimal medium to develop the medical product, determine the protocol for clinical application, and to assess the effectiveness of EDTA for local treatment of dystrophic calcinosis.
METHODS: Chemical analysis using Fourier Transform IR spectroscopy (\'FTIR\'), Raman microscopy, Powder X-Ray Diffraction (\'PXRD\'), and Transmission Electron Microscopy (\'TEM\') was undertaken of two distinct types of calcinosis deposits: paste and stone. Calcinosis sample titration with ethylenediaminetetraacetic acid (\'EDTA\') assessed the concentration at which the EDTA dissolved the calcinosis deposits in vitro.
RESULTS: FTIR spectra of the samples displayed peaks characteristic of hydroxyapatite, where signals attributable to the phosphate and carbonate ions were all identified. Polymorph characterization using Raman spectra were identical to a hydroxyapatite reference while the PXRD and electron diffraction patterns conclusively identified the mineral present as hydroxyapatite. TEM analysis showed differences of morphology between the samples. Rounded particles from stone samples were up to a few micron in size, while needle-like crystals from paste samples reached up to 0.5 µm in length. Calcium phosphate deposits were effectively dissolved with 3% aqueous solutions of EDTA, in vitro. Complete dissolution of both types of deposit was achieved in approximately 30 min using a molar ratio of EDTA/HAp of ≈ 300.
CONCLUSIONS: Stone and paste calcium-based deposits both comprise hydroxyapatite, but the constituent crystals vary in size and morphology. Hydroxyapatite is the only crystalline polymorph present in the SSc-related calcinosis deposits. Hydroxyapatite can be dissolved in vitro using a dosage of EDTA considered safe for clinical application. Further research is required to establish the optimal medium to develop the medical product, determine the protocol for clinical application, and to assess the effectiveness of EDTA for local treatment of dystrophic calcinosis.
摘要：
背景：对从SSc受试者中检索到的钙基沉积物的两种不同临床表现的无机部分进行详细的形态学分析，并确定这些沉积物的化学溶解适合临床使用。
方法：使用傅立叶变换红外光谱（\'FTIR\'）进行化学分析，拉曼显微术,粉末X射线衍射(\'PXRD\'),透射电子显微镜（“TEM”）是对两种不同类型的钙质沉积物进行的：糊状物和石头。用乙二胺四乙酸(\'EDTA\')滴定钙质沉着症样品评估EDTA在体外溶解钙质沉着沉积物的浓度。
结果：样品的FTIR光谱显示了羟基磷灰石的特征峰，其中可归因于磷酸根和碳酸根离子的信号都被鉴定。使用拉曼光谱的多晶型物表征与羟基磷灰石参考相同，而PXRD和电子衍射图最终确定了存在为羟基磷灰石的矿物。TEM分析显示样品之间的形态差异。石头样品中的圆形颗粒大小可达几微米，而来自糊状样品的针状晶体的长度达到0.5µm。用3%的EDTA水溶液有效溶解磷酸钙沉积物，在体外。使用〜300的EDTA/HAp摩尔比，在大约30分钟内实现了两种类型的沉积物的完全溶解。
结论：Stone和paste钙基沉积物均包含羟基磷灰石，但是组成晶体的大小和形态各不相同。羟基磷灰石是SSc相关钙质沉积中存在的唯一结晶多晶型物。羟基磷灰石可以使用认为对临床应用安全的剂量的EDTA在体外溶解。需要进一步研究以建立开发医疗产品的最佳介质，确定临床应用方案，并评估EDTA局部治疗营养不良性钙质沉着的有效性。
方法：使用傅立叶变换红外光谱（\'FTIR\'）进行化学分析，拉曼显微术,粉末X射线衍射(\'PXRD\'),透射电子显微镜（“TEM”）是对两种不同类型的钙质沉积物进行的：糊状物和石头。用乙二胺四乙酸(\'EDTA\')滴定钙质沉着症样品评估EDTA在体外溶解钙质沉着沉积物的浓度。
结果：样品的FTIR光谱显示了羟基磷灰石的特征峰，其中可归因于磷酸根和碳酸根离子的信号都被鉴定。使用拉曼光谱的多晶型物表征与羟基磷灰石参考相同，而PXRD和电子衍射图最终确定了存在为羟基磷灰石的矿物。TEM分析显示样品之间的形态差异。石头样品中的圆形颗粒大小可达几微米，而来自糊状样品的针状晶体的长度达到0.5µm。用3%的EDTA水溶液有效溶解磷酸钙沉积物，在体外。使用〜300的EDTA/HAp摩尔比，在大约30分钟内实现了两种类型的沉积物的完全溶解。
结论：Stone和paste钙基沉积物均包含羟基磷灰石，但是组成晶体的大小和形态各不相同。羟基磷灰石是SSc相关钙质沉积中存在的唯一结晶多晶型物。羟基磷灰石可以使用认为对临床应用安全的剂量的EDTA在体外溶解。需要进一步研究以建立开发医疗产品的最佳介质，确定临床应用方案，并评估EDTA局部治疗营养不良性钙质沉着的有效性。
