Inhibition of the amorphous calcium phosphate phase transformation reaction by polyphosphates and metal ions

Синтезированы гибридные нанокомпозиты на основе гидроксиапатита и аутофибрина в форме фибринового сгустка либо цитратной плазмы путем осаждения при pH 9. «Мягкие» условия осаждения и быстрое выделение нанокомпозитов способствовали сохранению биополимерной матрицы аутофибрина. Дестабилизация дополнительной фазы аморфного фосфата кальция с образованием стехиометрического гидроксиапатита обусловлена влиянием макромолекул фибрина. Формирование кальцийдефицитного гидроксиапатита с x« 0,1 и Ca / P 1,65 происходило в среде цитратной плазмы, который после 800 °С превращался в смесь гидроксиапатит / 3 -трикальцийфосфат. Синтез композитов на основе биомиметического апатита осуществляли при добавлении 30 об.% модельного раствора Simulated Body Fluid (SBF). Влияние ионов Mg, CO~, входящих в состав SBF, способствовало стабилизации аморфного фосфата кальция и образованию карбонатзамещенного гидроксиапатита, устойчивого к термическим превращениям до 800°С. Совокупное влияние аутофибрина и ионов введенного SBF позволило управлять составом минеральной составляющей гибридных нанокомпозитов без разрушения биополимерной матрицы. Hybrid composites based on hydroxyapatite and autofibrin were synthesized by precipitation in a medium with pH = 9. Soft precipitation conditions and rapid isolation of the composite precipitates favored preservation of a biopolymer matrix of autofibrin. An effect of fibrin macromolecules contributed to destabilization of the amorphous calcium phosphate phase and formation of stoichiometric hydroxyapatite. The medium of the citrated plasma stimulated precipitation of calcium-deficient hydroxyapatite with x « 0,1 and the Ca / P ration of 1,65 which transformed into the mixture of hydroxyapatite / 3 -tricalcium phosphate at 800 °С. Biomimetic apatite composites were synthesized with an addition of 30 vol. % of a Simulated Body Fluid (SBF) model solution. The effect of Mg, CO~ ions of SBF promoted the stabilization of amorphous calcium phosphate and formation of carbonated hydroxyapatite that exhibited thermal stability up to 800 °С. The cummulative effect of autofibrin and ions of induced SBF provided controlling composition of the mineral part of hybrid nanocomposites without disruption of an autofibrin matrix.

Download Full-text

Effect of amino acid on calcium phosphate phase transformation: attenuated total reflectance-infrared spectroscopy and chemometrics

Colloid & Polymer Science ◽

10.1007/s00396-018-4438-0 ◽

2018 ◽

Vol 297 (1) ◽

pp. 155-163 ◽

Cited By ~ 3

Author(s):

Yuta Otsuka ◽

Akira Ito ◽

Masaki Takeuchi ◽

Hideji Tanaka

Keyword(s):

Phase Transformation ◽

Infrared Spectroscopy ◽

Amino Acid ◽

Calcium Phosphate ◽

Attenuated Total Reflectance ◽

Total Reflectance ◽

Phosphate Phase ◽

Calcium Phosphate Phase

Download Full-text

Calcium Phosphate Phase Transformation Produced by the Interaction of the Portland Cement Component of White Mineral Trioxide Aggregate with a Phosphate-containing Fluid

Journal of Endodontics ◽

10.1016/j.joen.2007.07.008 ◽

2007 ◽

Vol 33 (11) ◽

pp. 1347-1351 ◽

Cited By ~ 176

Author(s):

Franklin R. Tay ◽

David H. Pashley ◽

Frederick A. Rueggeberg ◽

Robert J. Loushine ◽

R. Norman Weller

Keyword(s):

Phase Transformation ◽

Calcium Phosphate ◽

Portland Cement ◽

Mineral Trioxide Aggregate ◽

Phosphate Phase ◽

Calcium Phosphate Phase ◽

White Mineral

Download Full-text

Synchrotron X-Ray Microanalysis and Imaging of Synthetic Biological Calcium Carbonate in Comparison With Archaeological Samples Originating from the Large Cave of Arcy-sur-Cure (28000-24500 BP, Yonne, France)

Microscopy and Microanalysis ◽

10.1017/s1431927613013342 ◽

2013 ◽

Vol 19 (6) ◽

pp. 1523-1534 ◽

Cited By ~ 4

Author(s):

Emilie Chalmin ◽

Ina Reiche

Keyword(s):

Calcium Carbonate ◽

Calcium Phosphate ◽

Formation Process ◽

Amorphous Calcium Phosphate ◽

Analytical Methods ◽

X Ray ◽

Phosphate Phase ◽

Carbonate Formations ◽

Calcium Phosphate Phase ◽

Case Based

AbstractBiosynthetic calcite samples were investigated using combined synchrotron X-ray microspectroscopy mapping. These samples were prepared with bacteria isolated from the Large cave of Arcy-sur-Cure in which prehistoric figures are masked by an opaque calcite layer. The biotic or abiotic origin of this layer is the issue of the present work. As previously known, a large community of bacteria may be involved in the CaCO3 formation in caves. A mixture of calcite/vaterite was obtained from bacteria isolated from the cave. Therefore, we can offer conclusions on their calcifying capability. The rare presence of vaterite in cave environments may be treated as a marker of biotic carbonate formations. Moreover, an amorphous calcium phosphate phase was present in the form of a calcite/vaterite mixture in the biotic model samples. This mixture of phases could be used as a tracer of the biotic process of CaCO3 formation. These biotic tracer phases were not identified using the applied analytical methods in the natural samples taken from the opaque calcite layers that covered the prehistoric figures of the Large cave. In this case, based on the obtained results, the biotic calcite formation process is likely to be considered as an undetectable effect at minimum.

Download Full-text

Amorphous to crystalline calcium phosphate phase transformation at elevated pH

Journal of Colloid and Interface Science ◽

10.1016/0021-9797(82)90139-4 ◽

1982 ◽

Vol 89 (1) ◽

pp. 257-267 ◽

Cited By ~ 41

Author(s):

John L Meyer ◽

Cecilia C Weatherall

Keyword(s):

Phase Transformation ◽

Calcium Phosphate ◽

Phosphate Phase ◽

Calcium Phosphate Phase

Download Full-text

Evidence of calcium phosphate supersaturation in the loop of Henle

AJP Renal Physiology ◽

10.1152/ajprenal.1996.270.4.f604 ◽

1996 ◽

Vol 270 (4) ◽

pp. F604-F613 ◽

Cited By ~ 7

Author(s):

J. R. Asplin ◽

N. S. Mandel ◽

F. L. Coe

Keyword(s):

Calcium Phosphate ◽

Calcium Concentration ◽

Loop Of Henle ◽

X Ray ◽

Ion Interactions ◽

Collecting Ducts ◽

Phosphate Phase ◽

Dietary Phosphate ◽

Calcium Phosphate Phase

We have used published rat micropuncture data to construct a matrix of ion concentrations along the rat nephron. With an iterative computer model of known ion interactions, we calculated relative supersaturation ratios in all nephron segments. The collecting ducts and urine showed expected supersaturation with stone-forming salts. Fluid in the thin segment of the loop of Henle may be supersaturated with calcium carbonate and calcium phosphate under certain conditions. Because calculations cannot predict the actual course of crystallization, we made solutions to mimic, in vitro, presumed conditions in the loop of Henle. The solid phases that formed were analyzed by X-ray powder diffraction, electron microprobe, and infrared spectroscopy. All samples were identified as poorly crystallized or immature apatite. The descending limb of Henle's loop creates a unique condition as it extracts water but not sodium, bicarbonate, calcium, or phosphate, giving a calcium concentration at the bend of 3 mM, pH 7.4, and a phosphate concentration that varies from 0.8 to 48 mM, depending on parathyroid hormone and dietary phosphate. We conclude that conditions in the thin segment potentially could create a solid calcium phosphate phase, which may initiate nucleation of calcium oxalate salts in the collecting ducts, potentiating nephrolithiasis and nephrocalcinosis.

Download Full-text