AMORPHOUS CALCIUM PHOSPHATE FOR BI-PHASE CERAMICS PREPARATION D D . . Rabadjieva Rabadjieva 1 1 , , S S . . Tepavitcharova Tepavitcharova 1 , , R R . . Gergulova Gergulova 1 , , R R . . Titorenkova Titorenkova 2 , , E E . . Dyulgerova Dyulgerova 3 , O. Petrov , O. Petrov 2 [email protected]November, 2010, Bulgaria IGIC-BAS 1 Institute of General and Inorganic Chemistry, BAS 2 Institute of Mineralogy and Crystallography, BAS 3 Dental Medicine Faculty, University of Medicine, Sofia
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AMORPHOUS CALCIUM PHOSPHATE FOR BI-PHASE CERAMICS PREPARATION D. Rabadjieva 1, S. Tepavitcharova 1, R. Gergulova 1, R. Titorenkova 2, E. Dyulgerova 3,
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AMORPHOUS CALCIUM PHOSPHATE FOR BI-PHASE CERAMICS PREPARATION
1Institute of General and Inorganic Chemistry, BAS2Institute of Mineralogy and Crystallography, BAS 3Dental Medicine Faculty, University of Medicine, Sofia
INTRODUCTIONINTRODUCTION
Amorphous Calcium PhosphateACP
Ca(H2 PO
4 )2 .H
2 OC
a(HPO
4 )2 .2H
2 O
Ca8 (PO
4 )4 (HPO
4 )2 .5H
2 O
Ca
10 (PO4 )6 (O
H)2 Ca(H
2PO4)
2
-C
a 3(P
O 4) 2
a-Ca 3
(PO 4
) 2
Ca4(PO4)2О
Ca(HPO 4) 2
November, 2010, Bulgaria
Importance for the Biological system
They are the main inorganic component of body hard tissues
Biological apatite Nano-sizedPoorly crystallized Non-stoichiometric hydroxyapatite Including Na, K, Mg, Cl, F and CO3
Biological mineralization (biomineralization) process of in vivo formation of inorganic minerals
Deposition and Growing
of Calcium Phosphates in the organic matrix in the body fluids medium
November, 2010, Bulgaria
AIMS
To study the biomimetic synthesis and transformations of X-ray ACP in conventional, revised and modified with Glycine SBF in order to elucidate some elementary processes of hard tissue mineralization and of the influence of micro-environmental surroundings on synthesis and transformation processes.
The SBF composition influences the rate of polymorphous phase transformation. Both HCO3
- ions and Glycine accelerate the transformation rates but the effect is more pronounced by SBF with Glycine
The phase transformations leaded to changes in the chemical compositions of solid and liquid phases. Thermodynamic simulations reveal that these phenomena could be explained by the processes of dissolution/crystallization/co-crystallization/ion-exchange.
November, 2010, Bulgaria
November, 2010, Bulgaria
RESULTSRESULTSPreparation of bi-phase products
XRD analysis of the calcinated at 600oC precursor
10 20 30 40 50 60
2-theta-Scale
72 hmatured
initial
24 hmatured
Mg-substituted--TCP
HA
18.1 wt. % Mg-substituted -TCP and 81.9 wt. % HA
47.2 wt. % Mg-substituted -TCP and 52.8 wt. % HA
BIOMIMETIC APPROACH FOR PREPARATION OF MODIFIED CALCIUM
PHOSPHATES
i) precursor precipitation in SBF;
ii) precursor maturation in SBF;
iii)calcination of the maturated samples at 600oC.