Conventional, pulsed and high-field electron paramagnetic resonance for studying metal impurities in calcium phosphates of biogenic and synthetic origins

Gabbasov, B. F.; Gafurov, Marat; Starshova, Alena; Shurtakova, D. V.; Murzakhanov, Fadis F.; Mamin, G. V.; Orlinskiĭ, S. B.

doi:10.1016/j.jmmm.2018.02.039

Cited by 37 publications

(40 citation statements)

References 49 publications

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“…Owing to the electronic configuration of Fe 3+ ions (3d 5 , ground state 6 S 5/2 , electronic spin S = 5/2), it became possible to detect EPR signals for the Fe-doped HA. In the spectra (see Figure 7 ), three isotropic transitions are observed at g = 2.001, g = 4.27 and a shoulder at g = 9.3 for all iron concentrations which are distinctive features of Fe 3+ ions [ 60 , 61 ].…”

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confidence: 99%

Mesoporous Iron(III)-Doped Hydroxyapatite Nanopowders Obtained via Iron Oxalate

et al. 2021

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Mesoporous hydroxyapatite (HA) and iron(III)-doped HA (Fe-HA) are attractive materials for biomedical, catalytic, and environmental applications. In the present study, the nanopowders of HA and Fe-HA with a specific surface area up to 194.5 m2/g were synthesized by a simple precipitation route using iron oxalate as a source of Fe3+ cations. The influence of Fe3+ amount on the phase composition, powders morphology, Brunauer–Emmett–Teller (BET) specific surface area (S), and pore size distribution were investigated, as well as electron paramagnetic resonance and Mössbauer spectroscopy analysis were performed. According to obtained data, the Fe3+ ions were incorporated in the HA lattice, and also amorphous Fe oxides were formed contributed to the gradual increase in the S and pore volume of the powders. The Density Functional Theory calculations supported these findings and revealed Fe3+ inclusion in the crystalline region with the hybridization among Fe-3d and O-2p orbitals and a partly covalent bond formation, whilst the inclusion of Fe oxides assumed crystallinity damage and rather occurred in amorphous regions of HA nanomaterial. In vitro tests based on the MG-63 cell line demonstrated that the introduction of Fe3+ does not cause cytotoxicity and led to the enhanced cytocompatibility of HA.

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Section: Resultsmentioning

confidence: 99%

Mesoporous Iron(III)-Doped Hydroxyapatite Nanopowders Obtained via Iron Oxalate

et al. 2021

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“…Conventionally, the Mn 2+ -TCP systems are described by the spin-Hamiltonian ( Ĥ ) [ 30 ]: Ĥ = gβBS + D [ S 2 z − S ( S + 1)/3] + E ( S 2 x − S 2 y ) + ASI where S x , y , z are the projections of the electronic spin S = 5/2 on the principal direction of D ; D and E are the commonly used (axial and orthorhombic, correspondingly) parameters for ZFS; g and A are the isotropic g -factor and the hyperfine constant, respectively. In previous studies [ 27 , 31 ], it was shown for Mn-doped HA and TCP that g ≈ 2.001, D = 53(4) mT (1.5 GHz), Е = 14(3) mT (0.4 GHz), and A ≈ 9.4(4) mT. Our results ( Figure 3 ) can be satisfactorily described by g ≈ 2.003, D = 42(5) mT, Е = 9(2) mT, and A ≈ 9.5(5) mT.…”

Section: Resultsmentioning

confidence: 99%

In Vitro Properties of Manganese-Substituted Tricalcium Phosphate Coatings for Titanium Biomedical Implants Deposited by Arc Plasma

et al. 2020

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Bioactive manganese (Mn)-doped ceramic coatings for intraosseous titanium (Ti) implants are developed. Arc plasma deposition procedure is used for coatings preparation. X-ray Diffraction, Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy, and Electron Paramagnetic Resonance (EPR) methods are applied for coatings characterization. The coatings are homogeneous, composed of the main phase α-tricalcium phosphate (α-TCP) (about 67%) and the minor phase hydroxyapatite (about 33%), and the Mn content is 2.3 wt%. EPR spectroscopy demonstrates that the Mn ions are incorporated in the TCP structure and are present in the coating in Mn2+ and Mn3+ oxidation states, being aggregated in clusters. The wetting contact angle of the deposited coatings is suitable for cells’ adhesion and proliferation. In vitro soaking in physiological solution for 90 days leads to a drastic change in phase composition; the transformation into calcium carbonate and octacalcium phosphate takes place, and no more Mn is present. The absence of antibacterial activity against Escherichia coli, Enterococcus faecalis, and Pseudomonas aeruginosa bacteria strains is observed. A study of the metabolic activity of mouse fibroblasts of the NCTC L929 cell line on the coatings using the MTT (dye compound 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test demonstrates that there is no toxic effect on the cell culture. Moreover, the coating material supports the adhesion and proliferation of the cells. A good adhesion, spreading, and proliferative activity of the human tooth postnatal dental pulp stem cells (DPSC) is demonstrated. The developed coatings are promising for implant application in orthopedics and dentistry.

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“…From the analysis of 1 H ENDOR spectra, it could be supposed that vanadyl porphyrin complexes participate in the formation of asphaltene aggregates (at least in the studied films) through the functional groups rather than π − π interactions. It appears that application of double resonance techniques, especially at high frequencies (high magnetic fields), could significantly improve the understanding of the mechanisms of the aggregation (complex formation, self-organization) of various oil constituents and other high-molecular disordered systems of biogenic and synthetic origins [66,67]. 34…”

Section: Resultsmentioning

confidence: 99%

High-Field (3.4 T) ENDOR Investigation of Asphaltenes in Native Oil and Vanadyl Complexes by Asphaltene Adsorption on Alumina Surface

et al. 2019

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Vanadyl porphyrin complexes in asphaltenes from heavy (Karmalinskoye) oil and in asphaltene films obtained as a result of adsorption on the surface of aluminum oxide were studied by electron paramagnetic resonance (EPR) and double electron-nuclear resonance (ENDOR) in the W-band frequency range (microwave frequency of 95 GHz, magnetic field of 3.4 T). Mims ENDOR spectra from 1H and 27Al nuclei are observed. ENDOR spectra are different for native oil and asphaltenes from one side and the adsorbed samples from the other side while no significant changes in X- (microwave frequency of 9 GHz) or W-band EPR spectra are found. The results allow supposing that vanadyl porphyrin complexes (at least in the studied asphaltene films) participate in the formation of asphaltene aggregates through the functional groups rather than π−π interactions. The data show the feasibility of the commercial pulsed ENDOR approaches for the investigation of crude oils and their constituents under external influence.

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Conventional, pulsed and high-field electron paramagnetic resonance for studying metal impurities in calcium phosphates of biogenic and synthetic origins

Cited by 37 publications

References 49 publications

Mesoporous Iron(III)-Doped Hydroxyapatite Nanopowders Obtained via Iron Oxalate

Mesoporous Iron(III)-Doped Hydroxyapatite Nanopowders Obtained via Iron Oxalate

In Vitro Properties of Manganese-Substituted Tricalcium Phosphate Coatings for Titanium Biomedical Implants Deposited by Arc Plasma

High-Field (3.4 T) ENDOR Investigation of Asphaltenes in Native Oil and Vanadyl Complexes by Asphaltene Adsorption on Alumina Surface

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