Hydrogen-substituted β-tricalcium phosphate synthesized in organic media

Stähli, Christoph; Thüring, Jürg; Galea, Laëtitia; Tadier, Solène; Bohner, Marc; Döbelin, Nicola

doi:10.1107/s2052520616015675

Cited by 26 publications

(12 citation statements)

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“…The presence of a peak at 872 cm −1 confirms the presence of HPO 4 2− which is the only peak that differs in biological WH from the rest of the WH [20,45]. Moreover, the absence of peaks at 650 cm −1 and 3570 cm −1 confirmed that our samples were free from the secondary phase [7,31,43]. The peaks below 500 cm −1 are also present in the literature and are unidentified [35,51].…”

Section: Resultssupporting

confidence: 76%

“…On the other hand, a lot of works have been reported to explore the exact Ca:Mg:P ratios for the synthesis of pure WH phase, however; resulting in mixed phases [ 26 , 27 , 28 , 29 ]. Similarly, different CaPs intermediates like monetite, brushite and calcium deficient apatites have also been used as precursors to synthesize pure WH [ 30 , 31 ]. Recently, Magalhaes et al, in 2018, reported that whitlockite phase is stable between narrow pH range of 5 and 6 [ 8 ] while in other works acid pH 5.6 and pH 6–7 allows precipitation of β-TCMP and other magnesium containing whitlockite using common precursors [ 32 , 33 , 34 ] as well as under high-temperature hydrothermal conditions [ 35 ] to synthesize pure WH phase.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis, Characterization and Process Optimization of Bone Whitlockite

et al. 2020

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Whitlockite, being the second most abundant bio-mineral in living bone, finds huge applications in tissue regeneration and implants and its synthesis into its pure form has remained a challenge. Although precipitation of whitlockite phase has been reported recently in many publications, effects of various parameters to control such phase as well as conditions for the bulk preparation of this extremely important bio-mineral have not been investigated so far. In this work, we report the precipitation of pure whitlockite phase using common precursors. As reported in the literature, whitlockite is stable in a narrow pH range, therefore; optimization of pH for the stabilization of whitlockite phase has been investigated. Additionally, in order to narrow down the optimum conditions for the whitlockite precipitation, effect of temperature and heating conditions has also been studied. The obtained solids were characterized using powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). From PXRD analysis, it was observed that heating the precursor’s mixture at 100 °C with subsequent aging at the optimized pH resulted in the precipitation of pure whitlockite phase. These results were further confirmed by TGA, SEM and Raman spectroscopy analysis and it was confirmed that the conditions reported here favor whitlockite precipitation without formation of any secondary phase. These reaction conditions were further confirmed by changing all the parameters like aging, heating time, feed rate of precursors one by one. From PXRD analysis of these samples, it was concluded that not only pH but temperature, heating time, aging time and feed rate effect simultaneously on the precipitation of pure whitlockite phase and a subtle change in any of these parameters could lead to the formation of undesired stable secondary calcium phosphate phases.

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Section: Resultssupporting

confidence: 76%

Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization and Process Optimization of Bone Whitlockite

et al. 2020

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“…The bands at 1660, 1,548, and 1,246 cm −1 could be attributed to amide I, amide II, and amide III (arrow heads in Figure 3b), respectively, which are representatives of protein conformation (Magne et al, 2002). The absorption bands from 2,800 to 3,700 cm −1 and 1,638 cm −1 were attributable to moisture in the KBr pellets (Stähli et al, 2016), while the band at 2,350 cm −1 resulted from CO 2 gas. Commercial HAp showed a sharp and weak OH band at 3570 cm −1 ; this was indiscernible in the outer dentin, as is the case within dentin apatite (Magne et al, 2002).…”

Section: Property Of the Mineral Componentmentioning

confidence: 96%

“…In Figure 2b, the spectrum of the commercial HAp is shown for comparison. The absorption bands at 563, 602, and 1,032 cm −1 were due to PO 4 in apatite (Magne, Guicheux, Weiss, Pilet, & Daculsi, 2002;Stähli et al, 2016) and those at 1417 and 1,455 cm −1 were due to CO 3 that was replaced by PO 4 in the apatite structure (Emerson & Fischer, 1962;Bonel, 1972; Figure 2b). The bands at 1660, 1,548, and 1,246 cm −1 could be attributed to amide I, amide II, and amide III (arrow heads in Figure 3b), respectively, which are representatives of protein conformation (Magne et al, 2002).…”

Section: Property Of the Mineral Componentmentioning

confidence: 99%

Microstructure and mineral components of the outer dentin of Chimaera phantasma tooth plates

Iijima

Okumura

Kogure

et al. 2021

The Anatomical Record

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Tooth plates are a unique dental organ found in holocephalan fishes and lungfish. The chimaeroid tooth plates are atypical in terms of biomineralization, due to the hard tissue composition of whitlockite and apatite, while those of lungfish and other vertebrates are composed of apatite. The tooth plates are overlaid by a thin veneer-outer dentin-whose composition and role are not known. We aimed to test whether the outer dentin is composed of whitlockite or apatite, and whether it protects the osteodentin from abrasion and supports its overall strength. For this purpose, the mineral components and microstructure of outer dentin were studied. Our analyses of the outer dentin from the anterior (vomerine) tooth plates of Chimaera phantasma revealed that the mineral component is magnesium-and carbonate-containing calciumdeficient apatite and that the outer dentin has a three-zone structure. The main body is sandwiched between thin zones, which are less mineralized than the main body. Furthermore, in the outer zone and the main body, a higherorder structure was formed in accordance with the organization of wide and narrow fibers. Mineralization made the main body a composite of bundles of fibers and apatite. Transmission electron microscopy showed a structural relationship between apatite and the fibrous component on which the apatite was formed. Such a structure of the main body could be highly effective as a framework to resist abrasion and support the overall strength of the tooth plate.

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“…In a recent study, Stähli et al 21 revealed that the Ca(4) sites of WH were partially substituted by H + ions, accompanied by the inversion of P(1)O 4 tetrahedra. Upon substitution of H + ions at the Ca(4) sites, the presence of the protonated phosphate (HPO 4 2-) was confirmed in both the FT-IR spectra (Fig.…”

Section: Hco-n(nh 3 ) 2 + H 3 O + → Hcooh + (Ch 3 ) 2 -Nh 2+mentioning

confidence: 99%