Murzakhanov Fadis, Mamin Georgy Vladimirovich, Orlinskii Sergei, Goldberg Margarita, Petrakova Nataliya V, Fedotov Alexander Y, Grishin Peter, Gafurov Marat R, Komlev Vladimir S
Kazan Federal University, 18 Kremlevskaya Str., Kazan 420008, Russian Federation.
A.A. Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, Leninskiy Prospect 49, Moscow 119334, Russian Federation.
ACS Omega. 2021 Sep 23;6(39):25338-25349. doi: 10.1021/acsomega.1c03238. eCollection 2021 Oct 5.
Substituted calcium phosphates (CaPs) are vital materials for the treatment of bone diseases and repairing and replacement of defects in human hard tissues. In this paper, we present some applications of the rarely used pulsed electron paramagnetic resonance (EPR) and hyperfine interaction spectroscopy approaches [namely, electron spin-echo envelope modulation (ESEEM) and electron-electron double-resonance detected nuclear magnetic resonance (EDNMR)] to investigate synthetic CaPs (hydroxyapatite, tricalcium, and octacalcium phosphate) doped with various cations (Li, Na, Mn, Cu, Fe, and Ba). These resonance techniques provide reliable tools to obtain unique information about the presence and localization of impurity centers and values of hyperfine and quadrupole tensors. We show that revealed in CaPs by EPR techniques, radiation-induced stable nitrogen-containing species and carbonate radicals can serve as sensitive paramagnetic probes to follow CaPs' structural changes caused by cation doping. The most pulsed EPR, ESEEM, and EDNMR spectra can be detected at room temperature, reducing the costs of the measurements and facilitating the usage of pulsed EPR techniques for CaP characterization.
取代磷酸钙（CaP）是治疗骨疾病以及修复和替换人体硬组织缺损的重要材料。在本文中，我们展示了一些鲜少使用的脉冲电子顺磁共振（EPR）和超精细相互作用光谱方法[即电子自旋回波包络调制（ESEEM）和电子 - 电子双共振检测核磁共振（EDNMR）]在研究掺杂各种阳离子（锂、钠、锰、铜、铁和钡）的合成CaP（羟基磷灰石、磷酸三钙和磷酸八钙）方面的应用。这些共振技术提供了可靠的工具，以获取有关杂质中心的存在和定位以及超精细和四极张量值的独特信息。我们表明，通过EPR技术在CaP中揭示的辐射诱导稳定含氮物种和碳酸根自由基可作为灵敏的顺磁探针，以追踪阳离子掺杂引起的CaP结构变化。大多数脉冲EPR、ESEEM和EDNMR光谱可在室温下检测到，降低了测量成本，并便于使用脉冲EPR技术对CaP进行表征。
