Mineralization kinetics: The role of octacalcium phosphate in the precipitation of calcium phosphates

1984 ◽  
Vol 9 (1) ◽  
pp. 89-93 ◽  
Author(s):  
J.C. Heughebaert ◽  
G.H. Nancollas
Keyword(s):  
Calcium Phosphates ◽  
Octacalcium Phosphate ◽  
Mineralization Kinetics

scholarly journals Physico-chemical properties of calcium phosphates

2012 ◽  
Vol 59 (1) ◽  
pp. 7-21 ◽  
Author(s):  
Vesna Babic-Ivancic ◽  
Maja Dutour-Sikiric
Keyword(s):  
Calcium Phosphates ◽  
Chemical Properties ◽  
Organic Matrix ◽  
Octacalcium Phosphate ◽  
Carbonate Apatite ◽  
Organic Additives ◽  
Biologically Relevant ◽  
Beta Tricalcium Phosphate ◽  
Physico Chemical

Calcium phosphates have important role in biological and pathological mineralization. While only one of calcium phosphates, carbonate apatite, represents the main mineral component of teeth and bones, octacalcium phosphate, calcium hydrogenphosphate dihydrate and beta-tricalcium phosphate occur in pathological deposits. From the stand-point of chemists, processes of biological and pathological mineralization could be considered as deposition of inorganic phase within organic matrix, i.e. formation of inorganic-organic composites. Although this approach is very simplified at first glance, it allows clarification of important issues related to biomineralization (e.g. what is the role of individual components of organic matrix in the emerging solid tissue), and design and preparation of new materials for hard tissue regeneration (e.g. process of transformation after implantation). The importance of investigation about calcium phosphates will be presented through the overview of basic physico-chemical reactions related to the formation and transformation of biologically relevant calcium phosphates and their interaction with various organic additives in the laboratory.

scholarly journals The Influence of Different Classes of Amino Acids on Calcium Phosphates Seeded Growth

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4798
Author(s):  
Tea Mihelj Josipović ◽  
Monika Kovačević ◽  
Sarah Mateša ◽  
Marina Kostešić ◽  
Nives Matijaković ◽  
...  
Keyword(s):  
Amino Acids ◽  
Calcium Phosphate ◽  
Control Systems ◽  
Aspartic Acid ◽  
Significant Influence ◽  
Calcium Phosphates ◽  
Octacalcium Phosphate ◽  
Seeded Growth ◽  
Material Synthesis

Amino acids (AAs) attract attention for elucidating the role of proteins in biomineralization and the preparation of functionalized biomaterials. The influence that AAs exert on calcium phosphate (CaP) mineralization is still not completely understood, as contradictory results have been reported. In this paper, the influence of the addition of different classes of AAs, charged (L-aspartic acid, Asp; L-lysine, Lys), polar (L-asparagine, Asn; L-serine, Ser; L-tyrosine, Tyr), and non-polar (L-phenylalanine, Phe), on CaP growth in the presence of octacalcium phosphate (OCP) and calcium hydrogenphosphate dihydrate (DCPD) seeds was investigated. In control systems (without AAs), a calcium-deficient apatite (CaDHA) layer was formed on the surface of OCP, while a mixture of CaDHA and OCP in the form of spherical aggregates was formed on the surface of DCPD crystals. Charged and non-polar promoted, while polar AAs inhibited CaDHA formation on the OCP seeds. In the case of DCPD, Lys, Asp, and Phe promoted CaP formation, while the influence of other AAs was negligible. The most efficient promotor of precipitation in both cases was non-polar Phe. No significant influence of AAs on the composition and morphology of precipitates was observed. The obtained results are of interest for understanding biomineralization processes and additive controlled material synthesis.

A Comparative Study of Bioceramics In Vitro and In Vivo

2005 ◽  
Vol 284-286 ◽  
pp. 11-14 ◽  
Author(s):  
Yang Leng ◽  
Ren Long Xin ◽  
Ji Yong Chen
Keyword(s):  
Calcium Phosphates ◽  
Glass Ceramics ◽  
Octacalcium Phosphate ◽  
Rabbit Muscle ◽  
In Vivo Experiments ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Dental Applications

Bioactive calcium phosphate (Ca-P) formation in bioceramics surfaces in simulated body fluid (SBF) and in rabbit muscle sites was investigated. The examined bioceamics included most commonly used bioglass®, A-W glass-ceramics and calcium phosphates in orthopedic and dental applications. The Ca-P cyrstal structures were examined with single crystal diffraction patterns in transmission electron microscopy, which reduced possibility of misidentifying Ca-P phases. The experimental results show that capability of Ca-P formation considerably varied among bioceramics, particularly in vivo. Octacalcium phosphate (OCP) was revealed on the all types of bioceramics in vitro and in vivo experiments. This work leads us to rethink how to evaluate bioactivity of bioceramics and other orthopedic materials which exhibit capability of osteoconduction by forming direct bonding with bone.

scholarly journals Role of Aspartic and Polyaspartic Acid on the Synthesis and Hydrolysis of Brushite.

2019 ◽  
Vol 10 (1) ◽  
pp. 11 ◽  
Author(s):  
Katia Rubini ◽  
Elisa Boanini ◽  
Adriana Bigi
Keyword(s):  
Aspartic Acid ◽  
Octacalcium Phosphate ◽  
Physiological Solution ◽  
Cooperative Action ◽  
Phosphate Dihydrate ◽  
Mineral Phases ◽  
Carboxylate Groups ◽  
Hydrolysis Of ◽  
Thermal Stability Of

Dicalcium phosphate dihydrate (DCPD) is one of the mineral phases indicated as possible precursors of biological apatites and it is widely employed in the preparation of calcium phosphate bone cements. Herein, we investigated the possibility to functionalize DCPD with aspartic acid (ASP) and poly-aspartic acid (PASP), as models of the acidic macromolecules of biomineralized tissues, and studied their influence on DCPD hydrolysis. To this aim, the synthesis of DCPD was performed in aqueous solution in the presence of increasing concentrations of PASP and ASP, whereas the hydrolysis reaction was carried out in physiological solution up to three days. The results indicate that it is possible to prepare DCPD functionalized with PASP up to a polyelectrolyte content of about 2.3 wt%. The increase of PASP content induces crystal aggregation, reduction of the yield of the reaction and of the thermal stability of the synthesized DCPD. Moreover, DCPD samples functionalized with PASP display a slower hydrolysis than pure DCPD. On the other hand, in the explored range of concentrations (up to 10 mM) ASP is not incorporated into DCPD and does not influence its crystallization nor its hydrolysis. At variance, when present in the hydrolysis solution, ASP, and even more PASP, delays the conversion into the more stable phases, octacalcium phosphate and/or hydroxyapatite. The greater influence of PASP on the synthesis and hydrolysis of DCPD can be ascribed to the cooperative action of the carboxylate groups and to its good fit with DCPD structure.

Role of Mg2+, Sr2+, and F– ions in octacalcium phosphate crystallization

2017 ◽  
Vol 53 (12) ◽  
pp. 1261-1269 ◽  
Author(s):  
A. A. Tsyganova ◽  
O. A. Golovanova
Keyword(s):  
Octacalcium Phosphate

scholarly journals Proteolysis by MMP20 Prevents Aberrant Mineralization in Secretory Enamel

2019 ◽  
Vol 98 (4) ◽  
pp. 468-475 ◽  
Author(s):  
H. Yamazaki ◽  
B. Tran ◽  
E. Beniash ◽  
S.Y. Kwak ◽  
H.C. Margolis
Keyword(s):  
Octacalcium Phosphate ◽  
Crystal Formation ◽  
Mineral Formation ◽  
Enamel Matrix Proteins ◽  
Initial Development ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Rod Structures ◽  
Enamel Layer

The present study was conducted to investigate the role of proteolysis by matrix metalloproteinase 20 (MMP20) in regulating the initial formation of the enamel mineral structure during the secretory stage of amelogenesis, utilizing Mmp20-null mice that lack this essential protease. Ultrathin sagittal sections of maxillary incisors from 8-wk-old wild-type (WT), Mmp20-null (KO), and heterozygous (HET) littermates were prepared. Secretory-stage enamel ultrastructures from each genotype as a function of development were compared using transmission electron microscopy, selected area electron diffraction, and Raman microspectroscopy. Characteristic rod structures observed in WT enamel exhibited amorphous features in newly deposited enamel, which subsequently transformed into apatite-like crystals in older enamel. Surprisingly, initial mineral formation in KO enamel was found to proceed in the same manner as in the WT. However, soon after a rod structure began to form, large plate-like crystals appeared randomly within the developing KO enamel layer. As development continued, observed plate-like crystals became dominant and obscured the appearance of the enamel rod structure. Upon formation of these plate-like crystals, the KO enamel layer stopped growing in thickness, unlike WT and HET enamel layers that continued to grow at the same rate. Raman results indicated that Mmp20-KO enamel contains a significant portion of octacalcium phosphate, unlike WT enamel. Although normal in all other respects, large, randomly dispersed mineral crystals were observed in secretory HET enamel, although to a lesser extent than that seen in KO enamel, indicating that the level of MMP20 expression has a proportional effect on suppressing aberrant mineral formation. In conclusion, we found that proteolysis of extracellular enamel matrix proteins by MMP20 is not required for the initial development of the enamel rod structure during the early secretory stage of amelogenesis. Proteolysis by MMP20, however, is essential for the prevention of abnormal crystal formation during amelogenesis.

scholarly journals Three-dimensional printed bone scaffolds: The role of nano/micro-hydroxyapatite particles on the adhesion and differentiation of human mesenchymal stem cells

2017 ◽  
Vol 231 (6) ◽  
pp. 555-564 ◽  
Author(s):  
Marco Domingos ◽  
Antonio Gloria ◽  
Jorge Coelho ◽  
Paulo Bartolo ◽  
Joaquim Ciurana
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Calcium Phosphates ◽  
Three Dimensional ◽  
Human Mesenchymal Stem Cells ◽  
Mechanical Tests ◽  
Engineering Research

Bone tissue engineering is strongly dependent on the use of three-dimensional scaffolds that can act as templates to accommodate cells and support tissue ingrowth. Despite its wide application in tissue engineering research, polycaprolactone presents a very limited ability to induce adhesion, proliferation and osteogenic cell differentiation. To overcome some of these limitations, different calcium phosphates, such as hydroxyapatite and tricalcium phosphate, have been employed with relative success. This work investigates the influence of nano-hydroxyapatite and micro-hydroxyapatite (nHA and mHA, respectively) particles on the in vitro biomechanical performance of polycaprolactone/hydroxyapatite scaffolds. Morphological analysis performed with scanning electron microscopy allowed us to confirm the production of polycaprolactone/hydroxyapatite constructs with square interconnected pores of approximately 350 µm and to assess the distribution of hydroxyapatite particles within the polymer matrix. Compression mechanical tests showed an increase in polycaprolactone compressive modulus ( E) from 105.5 ± 11.2 to 138.8 ± 12.9 MPa (PCL_nHA) and 217.2 ± 21.8 MPa (PCL_mHA). In comparison to PCL_mHA scaffolds, the addition of nano-hydroxyapatite enhanced the adhesion and viability of human mesenchymal stem cells as confirmed by Alamar Blue assay. In addition, after 14 days of incubation, PCL_nHA scaffolds showed higher levels of alkaline phosphatase activity compared to polycaprolactone or PCL_mHA structures.

scholarly journals Phase transformation of calcium phosphates in the presence of glutamic acid

2011 ◽  
Vol 89 (7) ◽  
pp. 885-891 ◽  
Author(s):  
Tim W. T. Tsai ◽  
Wei-Ya Chen ◽  
Yao-Hung Tseng ◽  
Jerry C. C. Chan
Keyword(s):  
Phase Transformation ◽  
Calcium Phosphate ◽  
Glutamic Acid ◽  
Crystal Surface ◽  
Calcium Phosphates ◽  
Water Layer ◽  
Octacalcium Phosphate ◽  
Growth Direction ◽  
Transformation Kinetics ◽  
Transformation Pathway

This work describes a phase-transformation pathway of calcium phosphate in the presence of glutamic acid. The route follows the order starting from amorphous calcium phosphate and brushite, then octacalcium phosphate (OCP), and finally hydroxyapatite (HAp). The preferred growth direction of the intermediate OCP and the final HAp phases lies along the c axis. On the basis of our scanning electron microscopy, X-ray powder diffraction, and 31P solid-state NMR data, we suggest that the transformation is via the dissolution–reprecipitation process, which is facilitated in the presence of glutamic acid. The effect on the transformation kinetics is rationalized by the disruption of the water layer bound on the crystal surface.

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