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. 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. 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. 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.

中文翻译：

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营养不良性钙质沉着症：结构和形态组成，以及乙二胺四乙酸（“EDTA”）潜在局部治疗的评估


对从 SSc 受试者中取出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，并确定这些沉积物适合临床使用的化学溶解。使用傅里叶变换红外光谱 ('FTIR')、拉曼显微镜、粉末 X 射线衍射 ('PXRD') 和透射电子显微镜 ('TEM') 对两种不同类型的钙沉着沉积物进行化学分析：糊状和石头。用乙二胺四乙酸（“EDTA”）滴定钙质沉着样品评估了 EDTA 在体外溶解钙质沉着物的浓度。样品的 FTIR 光谱显示了羟基磷灰石的特征峰，其中磷酸盐和碳酸根离子的信号均被识别。使用拉曼光谱进行的多晶型表征与羟基磷灰石参考相同，而 PXRD 和电子衍射图最终确定该矿物为羟基磷灰石。 TEM 分析显示样品之间的形态差异。石材样品中的圆形颗粒尺寸可达几微米，而糊状样品中的针状晶体长度可达 0.5 微米。在体外，3% EDTA 水溶液可有效溶解磷酸钙沉积物。使用 EDTA/HAp 摩尔比约 300，两种类型的沉积物在大约 30 分钟内即可完全溶解。石质和糊状钙基沉积物均包含羟基磷灰石，但组成晶体的尺寸和形态各不相同。羟基磷灰石是与 SSc 相关的钙沉着矿床中存在的唯一结晶多晶型物。羟基磷灰石可以使用临床应用安全剂量的 EDTA 在体外溶解。 需要进一步的研究来确定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症的有效性。