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Dwivedi N, Siddiqui MA, Srivastava S, Sinha N. 1 H- 13 C cross-polarization kinetics to probe hydration-dependent organic components of bone extracellular matrix. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2023; 61:397-406. [PMID: 36946081 DOI: 10.1002/mrc.5347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 02/17/2023] [Accepted: 03/19/2023] [Indexed: 06/09/2023]
Abstract
Bone is a living tissue made up of organic proteins, inorganic minerals, and water. The organic component of bone (mainly made up of Type-I collagen) provides flexibility and tensile strength. Solid-state nuclear magnetic resonance (ssNMR) is one of the few techniques that can provide atomic-level structural insights of such biomaterials in their native state. In the present article, we employed the variable contact time cross-polarization (1 H-13 C CP) kinetics experiments to study the hydration-dependent atomic-level structural changes in the bone extracellular matrix (ECM). The natural abundant 13 C CP intensity of the bone ECM is measured by varying CP contact time and best fitted to the nonclassical kinetic model. Different relaxation parameters were measured by the best-fit equation corresponding to the different hydration conditions of the bone ECM. The associated changes in the measured parameters due to varying levels of hydration observed at different sites of collagen protein have provided its structural arrangements and interaction with water molecules in bone ECM. Overall, the present study reveals a better understanding of the kinetics of the organic part inside the bone ECM that will help in comprehending the disease-associated pathways.
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Affiliation(s)
- Navneet Dwivedi
- Centre of Biomedical Research, SGPGIMS Campus, Raebareli Road, Lucknow, 226014, India
- Department of Physics, Integral University, Lucknow, 226026, India
| | - Mohd Adnan Siddiqui
- Centre of Biomedical Research, SGPGIMS Campus, Raebareli Road, Lucknow, 226014, India
| | - Seema Srivastava
- Department of Physics, Integral University, Lucknow, 226026, India
| | - Neeraj Sinha
- Centre of Biomedical Research, SGPGIMS Campus, Raebareli Road, Lucknow, 226014, India
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Almhöjd US, Lingström P, Nilsson Å, Norén JG, Siljeström S, Östlund Å, Bernin D. Molecular Insights into Covalently Stained Carious Dentine Using Solid-State NMR and ToF-SIMS. Caries Res 2017; 51:255-263. [PMID: 28501859 DOI: 10.1159/000460828] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Accepted: 02/06/2017] [Indexed: 11/19/2022] Open
Abstract
Dyes currently used to stain carious dentine have a limited capacity to discriminate normal dentine from carious dentine, which may result in overexcavation. Consequently, finding a selective dye is still a challenge. However, there is evidence that hydrazine-based dyes, via covalent bonds to functional groups, bind specifically to carious dentine. The aim of this study was to investigate the possible formation of covalent bonds between carious dentine and 15N2-hydrazine and the hydrazine-based dye, 15N2-labelled Lucifer Yellow, respectively. Powdered dentine from extracted carious and normal teeth was exposed to the dyes, and the staining reactions were analysed using time-of-flight secondary ion mass spectrometry (ToF-SIMS), solid-state 13C-labelled nuclear magnetic resonance (NMR) and 15N-NMR spectroscopy. The results showed that 15N2-hydrazine and 15N2-labelled Lucifer Yellow both bind to carious dentine but not to normal dentine. It can thus be concluded that hydrazine-based dyes can be used to stain carious dentine and leave normal dentine unstained.
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Affiliation(s)
- Ulrica S Almhöjd
- Department of Cariology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Kruk J, Doskocz M, Jodłowska E, Zacharzewska A, Łakomiec J, Czaja K, Kujawski J. NMR Techniques in Metabolomic Studies: A Quick Overview on Examples of Utilization. APPLIED MAGNETIC RESONANCE 2017; 48:1-21. [PMID: 28111499 PMCID: PMC5222922 DOI: 10.1007/s00723-016-0846-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 10/10/2016] [Indexed: 05/08/2023]
Abstract
Metabolomics is a rapidly developing branch of science that concentrates on identifying biologically active molecules with potential biomarker properties. To define the best biomarkers for diseases, metabolomics uses both models (in vitro, animals) and human, as well as, various techniques such as mass spectroscopy, gas chromatography, liquid chromatography, infrared and UV-VIS spectroscopy and nuclear magnetic resonance. The last one takes advantage of the magnetic properties of certain nuclei, such as 1H, 13C, 31P, 19F, especially their ability to absorb and emit energy, what is crucial for analyzing samples. Among many spectroscopic NMR techniques not only one-dimensional (1D) techniques are known, but for many years two-dimensional (2D, for example, COSY, DOSY, JRES, HETCORE, HMQS), three-dimensional (3D, DART-MS, HRMAS, HSQC, HMBC) and solid-state NMR have been used. In this paper, authors taking apart fundamental division of nuclear magnetic resonance techniques intend to shown their wide application in metabolomic studies, especially in identifying biomarkers.
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Affiliation(s)
- Joanna Kruk
- Department of Organic Chemistry, Faculty of Pharmacy, Poznan University of Medical Sciences, Grunwaldzka 6 Str., 60-780 Poznan, Poland
| | - Marek Doskocz
- RootInnovation Sp. z o.o., Jana Matejki 11 Str., 50-333 Wrocław, Poland
| | - Elżbieta Jodłowska
- Department of Organic Chemistry, Faculty of Pharmacy, Poznan University of Medical Sciences, Grunwaldzka 6 Str., 60-780 Poznan, Poland
| | - Anna Zacharzewska
- Department of Organic Chemistry, Faculty of Pharmacy, Poznan University of Medical Sciences, Grunwaldzka 6 Str., 60-780 Poznan, Poland
| | - Joanna Łakomiec
- Department of Organic Chemistry, Faculty of Pharmacy, Poznan University of Medical Sciences, Grunwaldzka 6 Str., 60-780 Poznan, Poland
| | - Kornelia Czaja
- Department of Organic Chemistry, Faculty of Pharmacy, Poznan University of Medical Sciences, Grunwaldzka 6 Str., 60-780 Poznan, Poland
| | - Jacek Kujawski
- Department of Organic Chemistry, Faculty of Pharmacy, Poznan University of Medical Sciences, Grunwaldzka 6 Str., 60-780 Poznan, Poland
- Foundation for Development of Science and Business on Medical and Exact Sciences Area, Legnicka 65 Str., 54-206 Wrocław, Poland
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A solid-state NMR study of selenium substitution into nanocrystalline hydroxyapatite. Int J Mol Sci 2015; 16:11452-64. [PMID: 25997001 PMCID: PMC4463710 DOI: 10.3390/ijms160511452] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Revised: 04/09/2015] [Accepted: 04/29/2015] [Indexed: 11/16/2022] Open
Abstract
The substitution of selenium oxyanions in the hydroxyapatite structure was examined using multinuclear solid-state resonance spectroscopy (ssNMR). The study was supported by powder X-ray diffractometry (PXRD) and wavelength dispersion X-ray fluorescence (WD-XRF). Samples of pure hydroxyapatite (HA300) and selenate (HA300-1.2SeO4) or selenite (HA300-1.2SeO3) substituted hydroxyapatites were synthesized using the standard wet method and heated at 300 °C to remove loosely bonded water. PXRD data showed that all samples are single-phase, nanocrystalline hydroxyapatite. The incorporation of selenite and selenate ions affected the lattice constants. In selenium-containing samples the concentration of Se was very similar and amounted to 9.55% and 9.64%, for HA300-1.2SeO4 and HA300-1.2SeO3, respectively. PXRD and ssNMR data showed that the selenite doping significantly decreases the crystallite size and crystallinity degree. 31P and 1H NMR experiments demonstrated the developed surface hydrated layer in all samples, especially in HA300-1.2SeO3. 1H NMR studies showed the dehydroxylation of HA during the selenium oxyanions substitution and the existence of hydrogen bonding in structural hydroxyl group channels. 1H→77Se cross polarization NMR experiments indicated that selenites and selenates are located in the crystal lattice and on the crystal surface.
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McElderry JDP, Zhu P, Mroue KH, Xu J, Pavan B, Fang M, Zhao G, McNerny E, Kohn DH, Franceschi RT, Holl MMB, Tecklenburg MM, Ramamoorthy A, Morris MD. Crystallinity and compositional changes in carbonated apatites: Evidence from 31P solid-state NMR, Raman, and AFM analysis. J SOLID STATE CHEM 2013; 206:10.1016/j.jssc.2013.08.011. [PMID: 24273344 PMCID: PMC3835554 DOI: 10.1016/j.jssc.2013.08.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Solid-state (magic-angle spinning) NMR spectroscopy is a useful tool for obtaining structural information on bone organic and mineral components and synthetic model minerals at the atomic-level. Raman and 31P NMR spectral parameters were investigated in a series of synthetic B-type carbonated apatites (CAps). Inverse 31P NMR linewidth and inverse Raman PO43- ν1 bandwidth were both correlated with powder XRD c-axis crystallinity over the 0.3-10.3 wt% CO32- range investigated. Comparison with bone powder crystallinities showed agreement with values predicted by NMR and Raman calibration curves. Carbonate content was divided into two domains by the 31P NMR chemical shift frequency and the Raman phosphate ν1 band position. These parameters remain stable except for an abrupt transition at 6.5 wt% carbonate, a composition which corresponds to an average of one carbonate per unit cell. This near-binary distribution of spectroscopic properties was also found in AFM-measured particle sizes and Ca/P molar ratios by elemental analysis. We propose that this transition differentiates between two charge-balancing ion-loss mechanisms as measured by Ca/P ratios. These results define a criterion for spectroscopic characterization of B-type carbonate substitution in apatitic minerals.
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Affiliation(s)
| | - Peizhi Zhu
- Department of Chemistry and University of Michigan, Ann Arbor, MI 48109-1055
| | - Kamal H. Mroue
- Department of Chemistry and University of Michigan, Ann Arbor, MI 48109-1055
- Department of Chemistry and Biophysics, University of Michigan, Ann Arbor, MI 48109-1055
| | - Jiadi Xu
- Department of Chemistry and Biophysics, University of Michigan, Ann Arbor, MI 48109-1055
| | - Barbara Pavan
- Department of Chemistry and Science of Advanced Materials Program, Central Michigan University, Mt. Pleasant, MI, USA
| | - Ming Fang
- Department of Chemistry and University of Michigan, Ann Arbor, MI 48109-1055
| | - Guisheng Zhao
- Department of Chemistry School of Dentistry, University of Michigan, Ann Arbor, MI 48109-1055
| | - Erin McNerny
- Department of Chemistry School of Dentistry, University of Michigan, Ann Arbor, MI 48109-1055
| | - David H. Kohn
- Department of Chemistry School of Dentistry, University of Michigan, Ann Arbor, MI 48109-1055
| | - Renny T. Franceschi
- Department of Chemistry School of Dentistry, University of Michigan, Ann Arbor, MI 48109-1055
| | | | - Mary M.J. Tecklenburg
- Department of Chemistry and Science of Advanced Materials Program, Central Michigan University, Mt. Pleasant, MI, USA
| | - Ayyalusamy Ramamoorthy
- Department of Chemistry and University of Michigan, Ann Arbor, MI 48109-1055
- Department of Chemistry and Biophysics, University of Michigan, Ann Arbor, MI 48109-1055
| | - Michael D. Morris
- Department of Chemistry and University of Michigan, Ann Arbor, MI 48109-1055
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Seifert AC, Wright AC, Wehrli SL, Ong HH, Li C, Wehrli FW. 31P NMR relaxation of cortical bone mineral at multiple magnetic field strengths and levels of demineralization. NMR IN BIOMEDICINE 2013; 26:1158-66. [PMID: 23505120 PMCID: PMC3715596 DOI: 10.1002/nbm.2930] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 01/07/2013] [Accepted: 01/08/2013] [Indexed: 05/10/2023]
Abstract
Recent work has shown that solid-state (1) H and (31) P MRI can provide detailed insight into bone matrix and mineral properties, thereby potentially enabling differentiation of osteoporosis from osteomalacia. However, (31) P MRI of bone mineral is hampered by unfavorable relaxation properties. Hence, accurate knowledge of these properties is critical to optimizing MRI of bone phosphorus. In this work, (31) P MRI signal-to-noise ratio (SNR) was predicted on the basis of T1 and T2 * (effective transverse relaxation time) measured in lamb bone at six field strengths (1.5-11.7 T) and subsequently verified by 3D ultra-short echo-time and zero echo-time imaging. Further, T1 was measured in deuterium-exchanged bone and partially demineralized bone. (31) P T2 * was found to decrease from 220.3 ± 4.3 µs to 98.0 ± 1.4 µs from 1.5 to 11.7 T, and T1 to increase from 12.8 ± 0.5 s to 97.3 ± 6.4 s. Deuteron substitution of exchangeable water showed that 76% of the (31) P longitudinal relaxation rate is due to (1) H-(31) P dipolar interactions. Lastly, hypomineralization was found to decrease T1, which may have implications for (31) P MRI based mineralization density quantification. Despite the steep decrease in the T2 */T1 ratio, SNR should increase with field strength as B0 (0.4) for sample-dominated noise and as B0 (1.1) for coil-dominated noise. This was confirmed by imaging experiments.
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Affiliation(s)
- Alan C Seifert
- Laboratory for Structural NMR Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
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Mroue KH, MacKinnon N, Xu J, Zhu P, McNerny E, Kohn DH, Morris MD, Ramamoorthy A. High-resolution structural insights into bone: a solid-state NMR relaxation study utilizing paramagnetic doping. J Phys Chem B 2012; 116:11656-61. [PMID: 22953757 PMCID: PMC3460063 DOI: 10.1021/jp307935g] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The hierarchical heterogeneous architecture of bone imposes significant challenges to structural and dynamic studies conducted by traditional biophysical techniques. High-resolution solid-state nuclear magnetic resonance (SSNMR) spectroscopy is capable of providing detailed atomic-level structural insights into such traditionally challenging materials. However, the relatively long data-collection time necessary to achieve a reliable signal-to-noise ratio (S/N) remains a major limitation for the widespread application of SSNMR on bone and related biomaterials. In this study, we attempt to overcome this limitation by employing the paramagnetic relaxation properties of copper(II) ions to shorten the (1)H intrinsic spin-lattice (T(1)) relaxation times measured in natural-abundance (13)C cross-polarization (CP) magic-angle-spinning (MAS) NMR experiments on bone tissues for the purpose of accelerating the data acquisition time in SSNMR. To this end, high-resolution solid-state (13)C CPMAS experiments were conducted on type I collagen (bovine tendon), bovine cortical bone, and demineralized bovine cortical bone, each in powdered form, to measure the (1)H T(1) values in the absence and in the presence of 30 mM Cu(II)(NH(4))(2)EDTA. Our results show that the (1)H T(1) values were successfully reduced by a factor of 2.2, 2.9, and 3.2 for bovine cortical bone, type I collagen, and demineralized bone, respectively, without reducing the spectral resolution and thus enabling faster data acquisition. In addition, paramagnetic quenching of particular (13)C NMR resonances on exposure to Cu(2+) ions in the absence of mineral was also observed, potentially suggesting the relative proximity of three main amino acids in the protein backbone (glycine, proline, and alanine) to the bone mineral surface.
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Affiliation(s)
- Kamal H. Mroue
- Biophysics, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
- Department of Chemistry, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
| | - Neil MacKinnon
- Biophysics, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
- Department of Chemistry, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
| | - Jiadi Xu
- Biophysics, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
- Department of Chemistry, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
| | - Peizhi Zhu
- Department of Chemistry, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
| | - Erin McNerny
- School of Dentistry, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
| | - David H. Kohn
- School of Dentistry, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
| | - Michael D. Morris
- Department of Chemistry, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
| | - Ayyalusamy Ramamoorthy
- Biophysics, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
- Department of Chemistry, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
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Incorporation of carbonate and magnesium ions into synthetic hydroxyapatite: The effect on physicochemical properties. J Mol Struct 2011. [DOI: 10.1016/j.molstruc.2010.11.058] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Kaflak A, Kolodziejski W. Kinetics of 1H --> 31P NMR cross-polarization in bone apatite and its mineral standards. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2008; 46:335-41. [PMID: 18306247 DOI: 10.1002/mrc.2207] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Kinetics of NMR cross-polarization (CP) from protons to phosphorus-31 nuclei was studied in the following samples: mineral of whole human bone, apatite prepared from bone, natural brushite, synthetic hydroxyapatite (hydrated and calcined), and synthetic carbonatoapatite of type B with 9 wt% of CO(3) (2-). In order to avoid an effect of magic angle spinning on CP and relaxation, the experiments were carried out on static samples. Parameters of the CP kinetics were discussed for trabecular and cortical bone tissue from adult subjects in comparison to the synthetic mineral standards. It was found that carbonatoapatite shows similar CP behavior to the bone mineral. Both materials undergo two-component CP kinetics. The fast-relaxing classical component is from the surface of apatite crystals and the slow-relaxing nonclassical component comes from the crystal interior. The components have been unambiguously assigned using inverse CP from phosphorus-31 to protons. The study provides information on a structured water layer, which covers crystal surface of carbonato- and bone apatite. The layer encompasses ca 40% of apatite phosphorus and its thickness is more than ca 2 nm.
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Affiliation(s)
- Agnieszka Kaflak
- Medical University of Warsaw, Faculty of Pharmacy, Department of Inorganic and Analytical Chemistry, ul. Banacha 1, 02-097 Warszawa, Poland
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Tseng YH, Mou Y, Chen PH, Tsai TWT, Hsieh CI, Mou CY, Chan JCC. Solid-state P-31 NMR study of the formation of hydroxyapatite in the presence of glutaric acid. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2008; 46:330-334. [PMID: 18306172 DOI: 10.1002/mrc.2096] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We demonstrate that glutaric acid can be used to prepare nanorods of hydroxyapatite under hydrothermal condition at 100 degrees C with a Ca(2+):glutaric acid molar ratio of 1:4. Frequency-switched Lee-Goldburg irradiation is employed to obtain high-resolution (31)P{(1)H} correlation spectra of the reaction mixture at two different reaction periods, from which it is shown that octacalcium phosphate is the precursor phase of the final hydroxyapatite product. In addition, the spectra show that a substantial amount of water molecules is trapped between the glutaric acid and the hydroxyapatite surface, indicating that water molecules may play a prominent role in the noncovalent interaction of the glutaric acid and the HAp surface.
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Affiliation(s)
- Yao-Hung Tseng
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, Taiwan
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Kaflak A, Kolodziejski W. Phosphorus-31 spin-lattice NMR relaxation in bone apatite and its mineral standards. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2007; 31:174-83. [PMID: 17621456 DOI: 10.1016/j.ssnmr.2007.04.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2007] [Revised: 04/25/2007] [Accepted: 04/25/2007] [Indexed: 05/13/2023]
Abstract
Phosphorus-31 spin-lattice relaxation, both in the laboratory (B(0)=4.7 T) and rotating frame (B(1)=2.2 mT), was studied in the following samples: mineral of whole human bone (samples B1-B6), apatite prepared from bone (BHA), natural brushite (BRU), synthetic hydroxyapatite hydrated (HAh) and calcined (HAc), and synthetic carbonatoapatite of type B (CHA-B) with 9 wt% of CO(3)(2-). The T(1)(P) relaxation time was determined directly using the saturation recovery technique, while the T(1 rho)(P) relaxation time was measured via (1)H-->(31)P CP by incrementing the (31)P spin-lock. In order to avoid an effect of magic-angle spinning (MAS) on CP and relaxation, the experiments were carried out on static samples. The (31)P spin-lattice relaxation was discussed for trabecular and cortical bone tissue from adult subjects in comparison to the synthetic mineral standards. None of the reference materials has matched accurately the relaxation behaviour of the bone mineral. The most striking differences between the examined substances were observed for T(1)(P), which for human bone was sample dependent and appeared in the range 55-100 s, while for HAh, HAc, and CHA-B was 7.2, 10.0, and 25.8 s, respectively. Possible reasons of so large relaxation diversity were discussed. It has been suggested that T(1)(P) of apatites is to some extent dependent on the concentration of the structural hydroxyl groups, and this in turn is controlled by the material crystallinity. It was also found that T(1)(P) decreased on hydration by ca. 30%. For T(1rho)(P), both its magnitude and dependence on the CP contact time gave useful structural information. The dehydrated samples (HAc and BHA) had long T(1 rho)(P) over 250 ms. Those, which contained water, either structural (BRU) or adsorbed on the crystal surface (HAh, CHA-B, and B1-B6), had shorter T(1 rho)(P) below 120 ms. It was concluded that the effect of water on T(1 rho)(P) is much more pronounced than on T(1)(P). The interpretation has involved P-OH groups and adsorbed water, which cover the apatite crystal surface.
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Affiliation(s)
- Agnieszka Kaflak
- Medical University of Warsaw, Faculty of Pharmacy, Department of Inorganic and Analytical Chemistry, ul Banacha 1, Warszawa, Poland
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Tseng YH, Tsai YL, Tsai TWT, Lin CP, Huang SH, Mou CY, Chan JCC. Double-quantum filtered heteronuclear correlation spectroscopy under magic angle spinning. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2007; 31:55-61. [PMID: 17276042 DOI: 10.1016/j.ssnmr.2007.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2006] [Revised: 12/29/2006] [Accepted: 01/02/2007] [Indexed: 05/13/2023]
Abstract
We present a simple experimental method to extract the van Vleck second moment of a multiple-spin system under high-resolution condition. The idea is to incorporate a double-quantum (DQ) filter into the pulse sequence of heteronuclear correlation spectroscopy so that a DQ excitation profile can be obtained by measuring a series of 2D spectra. The effects of spinning frequency and proton decoupling are demonstrated on the measurements of two model compounds, viz. hydroxyapatite and brushite. Based on the results obtained for the model compounds, the P-31 homonuclear second moment of the apatite component in rat dentin is characterized. The method is generally suited for the study of bone, enamel and dentin.
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Affiliation(s)
- Yao-Hung Tseng
- Department of Chemistry, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei, Taiwan
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