In Vitro Effects of Cementum Protein 1 (CEMP1) on Calcium Phosphate Crystal Formation and its Role During the Mineralization Process

2009 ◽  
Vol 1244 ◽  
Author(s):  
Enrique Romo-Arévalo ◽  
Eduardo Villarreal-Ramírez ◽  
Juan L. Chávez-Pacheco ◽  
Cristina Piña-Barba ◽  
M. Aguilar-Franco ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Molecular Mechanisms ◽  
Periodontal Regeneration ◽  
Octacalcium Phosphate ◽  
Cellular Adhesion ◽  
Crystal Nucleation ◽  
Crystal Formation ◽  
Calcium Phosphate Crystal ◽  
Hydroxyapatite Crystals

ABSTRACTCementum contains specific molecules that could serve to identify, isolate and characterize the cementoblast lineage and to determine the cellular and molecular mechanisms that regulate the cementogenesis process, since it plays a key role during the periodontal regeneration process. One of these molecules is the human cementum protein 1 (CEMP1); which has a molecular weight of 25,9 kDa. In vitro experiments have shown that CEMP1 promotes cellular adhesion and differentiation. In addition, this protein has been implied in regulating the degree of deposition, composition and morphology of hydroxyapatite crystals formed by putative cementoblast in vitro. Therefore, it is possible that CEMP1 promotes the formation, growth and regulates the morphology of hydroxyapatite crystals in vitro. We have produced a human recombinant CEMP1 (hrCEMP1) in a prokaryotic system. The hrCEMP1 purification was realized using the column NiTA HisPrep FF/16. Assays of calcium phosphate crystal growth were realized by means of capillary counterdiffusion system. Our results demonstrated that hrCEMP1 promotes octacalcium phosphate crystal nucleation and possesses high affinity for hydroxyapatite. We infer that hrCEMP1 plays a key role during the regeneration of mineralized tissues.

Calcium Phosphate Crystal Formation inEscherichia Colifrom Human Urine: An in Vitro Study

1982 ◽  
Vol 127 (1) ◽  
pp. 184-185 ◽  
Author(s):  
Marc S. Cohen ◽  
C.P. Davis ◽  
Edmund W. Czerwinski ◽  
Michael M. Warren
Keyword(s):  
Calcium Phosphate ◽  
Human Urine ◽  
In Vitro Study ◽  
Vitro Study ◽  
Crystal Formation ◽  
Calcium Phosphate Crystal

XRD study of calcium-phosphate crystal formation on dentine surface

2013 ◽  
Author(s):  
Nadezda O. Bessudnova ◽  
Alexandr Skaptsov ◽  
Sergey B. Venig ◽  
Andrey N. Gribov ◽  
Vsevolod S. Atkin
Keyword(s):  
Calcium Phosphate ◽  
Crystal Formation ◽  
Xrd Study ◽  
Calcium Phosphate Crystal ◽  
Dentine Surface

scholarly journals Phosphoserine Functionalized Cements Preserve Metastable Phases, and Reprecipitate Octacalcium Phosphate, Hydroxyapatite, Dicalcium Phosphate, and Amorphous Calcium Phosphate, during Degradation, In Vitro

2019 ◽  
Vol 10 (4) ◽  
pp. 54 ◽  
Author(s):  
Joseph Lazraq Bystrom ◽  
Michael Pujari-Palmer
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Octacalcium Phosphate ◽  
Ionic Concentration ◽  
Strong Adhesion ◽  
Acidic Conditions ◽  
Rapid Transformation ◽  
Comparable Mass

Phosphoserine modified cements (PMC) exhibit unique properties, including strong adhesion to tissues and biomaterials. While TTCP-PMCs remodel into bone in vivo, little is known regarding the bioactivity and physiochemical changes that occur during resorption. In the present study, changes in the mechanical strength and composition were evaluated for 28 days, for three formulations of αTCP based PMCs. PMCs were significantly stronger than unmodified cement (38–49 MPa vs. 10 MPa). Inclusion of wollastonite in PMCs appeared to accelerate the conversion to hydroxyapatite, coincident with slight decrease in strength. In non-wollastonite PMCs the initial compressive strength did not change after 28 days in PBS (p > 0.99). Dissolution/degradation of PMC was evaluated in acidic (pH 2.7, pH 4.0), and supersaturated fluids (simulated body fluid (SBF)). PMCs exhibited comparable mass loss (<15%) after 14 days, regardless of pH and ionic concentration. Electron microscopy, infrared spectroscopy, and X-ray analysis revealed that significant amounts of brushite, octacalcium phosphate, and hydroxyapatite reprecipitated, following dissolution in acidic conditions (pH 2.7), while amorphous calcium phosphate formed in SBF. In conclusion, PMC surfaces remodel into metastable precursors to hydroxyapatite, in both acidic and neutral environments. By tuning the composition of PMCs, durable strength in fluids, and rapid transformation can be obtained.

Biomimetic Mineralization and Bioactivity of Phosphorylated Chitosan

2005 ◽  
Vol 288-289 ◽  
pp. 429-432 ◽  
Author(s):  
Zhi Qing Chen ◽  
Quan Li Li ◽  
Quan Zen ◽  
Gang Li ◽  
Hao Bin Jiang ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Crystal Nucleation ◽  
Osteoblast Proliferation ◽  
Biomimetic Mineralization ◽  
P Content ◽  
Proliferation And Differentiation ◽  
Nucleation Growth

Phosphorylated chitosans were synthesized as templates to manipulate hydroxyapatite (HA) crystal nucleation, growth and microstructure. Two kinds of insoluble phosphorylated chitosan were soaked in saturated Ca(OH)2 solution for 4 d and in 1.5× SBF (simulated body fluid) solutions for 14 d at 37 °C for biomimetic mineralization. A lower [P]-content of phosphorylated chitosan promoted greater mineralization than higher [P]-content. Phosphorylated chitosan inhibited osteoblast proliferation and differentiation in vitro, while calcium phosphate phosphorylated chitosan composites did not.

In Vitro Study Bioactivity of HA/UHMWPE Nanocomposites

2007 ◽  
Vol 342-343 ◽  
pp. 701-704
Author(s):  
Li Ming Fang ◽  
Yang Leng ◽  
Ping Gao
Keyword(s):  
Molecular Weight ◽  
Calcium Phosphate ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
In Vitro Study ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Octacalcium Phosphate ◽  
Tof Sims ◽  
Ultrahigh Molecular Weight

Bioactivity of hydroxyapatite reinforced ultrahigh molecular weight polyethylene (HA/UHMWPE) nanocomposites with HA volume content of 10~50 % was evaluated by simulated body fluid (SBF) immersion. The effect of HA content on the capability for calcium phosphate (Ca- P) induction was studied. It was found that Ca-P deposition covered the whole surface of the composite with 30 vol. % of HA after immersion for 1 day and the layer grew to around 10 0m thick in one-week immersion, while there was few nucleus formed for composites with HA content lower than 30 vol. % after one-week immersion. The Ca-P structure was identified as octacalcium phosphate (OCP) by SEM, TEM, and ToF-SIMS.

Stimulation of calcium phosphate crystal formation by implant surfaces with electret properties

2015 ◽  
Vol 15 (4) ◽  
pp. 200-203
Author(s):  
V.V. Starikov ◽  
S.L. Starikova ◽  
A.G. Mamalis ◽  
S.N. Lavrynenko
Keyword(s):  
Calcium Phosphate ◽  
Crystal Formation ◽  
Calcium Phosphate Crystal ◽  
Stimulation Of

In Vitro Biocompatibility Testing of Collagen-Calcium Phosphate Composites Using Human Bone Derived Osteoblasts

1998 ◽  
Vol 550 ◽  
Author(s):  
A.C. Lawson ◽  
M. Oyama ◽  
M.E. Emerton ◽  
M.J.O. Francis ◽  
A.H.R.W. Simpson ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Calcium Phosphate ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Transforming Growth Factor ◽  
Cell Attachment ◽  
Octacalcium Phosphate ◽  
Histochemical Staining ◽  
Human Bone

AbstractHuman bone derived osteoblasts were cultured on collagen-calcium phosphate composites. The ability of the substrates to support cell attachment, proliferation and bone formation was assessed using histochemical staining for alkaline phosphatase activity and immunolocalisation of transforming growth factor- β1and type 1 collagen. The effect of calcium phosphate phase and crystal size was investigated and the calcified samples compared with uncalcified collagen. Osteoblasts adhere to the collagen-calcium phosphate composites and express a mature osteoblast phenotype in vitro. Cell adhesion was greater on unmineralised collagen than on the mineralised composites, however, these cells were less differentiated. The presence of larger crystals seemed to have a detrimental effect on the cells, reducing proliferation and alkaline phosphatase activity. There was no discernible difference between the effect of hydroxyapatite and octacalcium phosphate on the cells.

Effect of Octacalcium Phosphate Ionic Dissolution Products on Osteoblastic Cell Differentiation

2007 ◽  
Vol 361-363 ◽  
pp. 31-34 ◽  
Author(s):  
Takahisa Anada ◽  
Akihiro Araseki ◽  
Shou Matsukawa ◽  
Tomokazu Yamasaki ◽  
Shinji Kamakura ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Conditioned Medium ◽  
Molecular Mechanisms ◽  
Octacalcium Phosphate ◽  
Osteoblastic Cell ◽  
Mouse Bone Marrow ◽  
Phosphate Ions ◽  
Proliferation And Differentiation

Our previous studies suggested that synthetic octacalcium phosphate (OCP) enhances bone regeneration more than hydroxyapatite (HA). However, the molecular mechanisms to induce osteogenic phenotype in osteoblast by OCP have not been identified. OCP tended to convert into an apatite structure in vivo and in vitro, and its process was accompanied by calcium consumption from the surrounding solution and the release of phosphate ions into the solution at a physiological condition. The present study was designed to investigate whether the dissolution of ionic products of OCP affects on proliferation and differentiation of mouse bone marrow stromal ST-2 cells in vitro. The number of cells treated with OCP-conditioned medium was slightly decreased in comparison to that of control at day 7. On the other hand, the level of alkaline phosphatase activity increased in OCP-conditioned medium. These results demonstrated that OCP is capable of inducing osteoblastic cell differentiation in ST-2 cells.

scholarly journals Stimulation of precipitation of calcium phosphate by matrix vesicles

1978 ◽  
Vol 170 (3) ◽  
pp. 681-691 ◽  
Author(s):  
R Felix ◽  
W Herrmann ◽  
H Fleisch
Keyword(s):  
Calcium Phosphate ◽  
Matrix Vesicles ◽  
Crystal Formation ◽  
Freezing And Thawing ◽  
Minimum Concentration ◽  
Vesicle Preparation ◽  
Before And After ◽  
Stimulation Of

The ability of matrix vesicles isolated from the epiphysial growth plate of 6-week-old chicks to facilitate the precipitation of calcium phosphate was studied in vitro. The vesicles lowered the minimum concentration product [ca2+]X[p1] needed to induce crystal formation, thereby showing the vesicles are nucleators of crystallization. After freezing and thawing the vesicles at pH6.0, part but not all of this ability to nucleate disappeared. Freezing and thawing markedly decreased the Ca and Pi content of the vesicles, suggesting that part of the nucleating activity may have been due to mineral already present. After removal of the mineral the residual nucleating activity could be destroyed by extracting the vesicles with lipid solvents or by treatment with enzymes such as phosphoilipase C, neuraminidase or proteinase. Matrix vesicles obtained from chicks treated with 1-hydroxyethane-1, 1-diphosphonate, a compound that inhibits calcification in vivo, showed impaired nucleating activity, both before and after treatment at pH6.0. The vesicle preparation bound some diphosphonate in vitro, probably to the mineral present in the preparation, since no binding could be detected in vesicles preincubated at pH6.0. No difference was found in the nucleating activity of vesicles isolated from rachitic chicks which had or had not received cholacalciferol 48 h before death. These results suggest that matrix vesicles possess intrinsic nucleating activity that may be important in biological calcification.

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