SURFACE MORPHOLOGIES ON THE ADDITION OF TiO2 TO CALCIUM PHOSPHATE BIO-GLASS

2007 ◽  
Vol 19 (06) ◽  
pp. 389-394
Author(s):  
Wen C. Say ◽  
Chin C. Yeh ◽  
Chih-Hwa Chen
Keyword(s):  
Titanium Dioxide ◽  
Calcium Phosphate ◽  
Calcium Ion ◽  
Calcium Pyrophosphate ◽  
Second Step ◽  
Crystalline Phases ◽  
Mixed Solutions ◽  
Surface Morphologies ◽  
Hydroxyapatite Formation

Titanium dioxide is added into calcium phosphate bio-glass (CPG) to have crystalline phases of titanium phosphoric ( TiP 2 O 7) and calcium phosphoric ( CaP 2 O 7) on its surfaces. The bio-glass synthesis with the addition of titanium dioxide herein is denoted as TCPG. To elucidate their surface morphologies, both specimens of CPG and TCPG were immersed in Hanks' solution for two days before soaking in the mixed solutions of ( NH 4)2 HPO 4 and Ca ( NO 3)2 at 70°. Crystalline layers of titanium phosphoric were observed on the surfaces of TCPG from immersing in Hanks' solution. After which calcium pyrophosphate appeared on the second step of soaking process from the calcium ion contained solutions. Due to the absence of crystalline phases on the surfaces of CPG specimen, it can be deduced that the addition of titania ( TiO 2) causes the hydroxyapatite formation on the surface of bio-glass.

scholarly journals Structure–activity relationship of inhibitors of hydroxyapatite formation

1979 ◽  
Vol 184 (1) ◽  
pp. 181-184 ◽  
Author(s):  
G Williams ◽  
J D Sallis
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Strong Inhibition ◽  
Structure Activity ◽  
New Findings ◽  
Fructose 1,6 Bisphosphate ◽  
Relationship Of ◽  
Hydroxyapatite Formation

The relative abilities of some compounds to inhibit the transformation of amorphous calcium phosphate into hydroxyapatite were determined. Organic diphosphates, fructose 1,6-bisphosphate, pyrophosphate, imidodiphosphate and 3-phospholycerate all inhibited to various degrees. Strong inhibition was observed with phosphonoformate, and phosphocitrate proved to be the most powerful of the inhibitors examined. On the basis of these new findings an improved concept of the structure–activity relationship of inhibitors is proposed and mechanisms for inhibitor action are discussed.

Bioactivity Assessment of Apatite Nuclei-PVDF Composite Thin Films

2018 ◽  
Vol 782 ◽  
pp. 78-83
Author(s):  
Hasnat Zamin ◽  
Takeshi Yabutsuka ◽  
Shigeomi Takai
Keyword(s):  
Thin Films ◽  
Calcium Phosphate ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Polyvinylidene Fluoride ◽  
Solution Casting ◽  
Casting Technique ◽  
Doctor Blade ◽  
Solution Casting Technique ◽  
Hydroxyapatite Formation

Particles of calcium phosphate were precipitated by raising the temperature and the pH of simulated body fluid (SBF) named Apatite Nuclei (AN). AN and polyvinylidene fluoride (PVDF) composites thin films with different weight percentages of AN in PVDF were fabricated by solution casting technique, using doctor blade method. In order to assess the bioactivity, the thin films were soaked in simulated body fluid (SBF). It was found that the film containing 30 wt.% of AN in PVDF actively induced hydroxyapatite formation in 3 days soaking period in SBF.

Fabrication of Hydroxyapatite Microcapsule Containing Vitamin B12 for Sustained-Release

2014 ◽  
Vol 631 ◽  
pp. 326-331 ◽  
Author(s):  
Takeshi Yabutsuka ◽  
Kazuma Iwahashi ◽  
Hiroki Nakamura ◽  
Takeshi Yao
Keyword(s):  
Calcium Phosphate ◽  
Simulated Body Fluid ◽  
Sustained Release ◽  
Body Fluid ◽  
Fine Particles ◽  
Vitamin B ◽  
Hydroxyapatite Formation

When either the pH or temperature of simulated body fluid (SBF) are raised, fine particles of calcium phosphate are precipitated. We found that these fine particles actively induce hydroxyapatite formation from body fluid or SBF and named the particles Apatite Nuclei. In this study, we fabricated hollow hydroxyapatite microcapsules by using Apatite Nuclei. We inserted vitamin B12 in the hollow microcapsule and examined thesustained-release properties.

Fabrication of Bioactive Zirconia by Doubled Sandblasting Process and Incorporation of Apatite Nuclei

2019 ◽  
Vol 829 ◽  
pp. 151-156
Author(s):  
Hasnat Zamin ◽  
Takeshi Yabutsuka ◽  
Shigeomi Takai ◽  
Hiroshi Sakaguchi ◽  
Takeshi Yao
Keyword(s):  
Calcium Phosphate ◽  
Fine Particles ◽  
Hydroxyapatite Formation

In this study, we aimed to introduce bioactivity to bioinert zirconia by performing sandblasting process and subsequently depositing apatite nuclei (AN), which are fine particles of calcium phosphate precipitated by raising pH of SBF, on the surface of the zirconia samples. By soaking the AN treated zirconia samples in SBF, hydroxyapatite formation was observed in 1 day and high hydroxyapatite-forming ability was attained.

scholarly journals Calcium Phosphate Deposition Disease in Great Danes

1982 ◽  
Vol 19 (5) ◽  
pp. 464-485 ◽  
Author(s):  
J. C. Woodard ◽  
R. P. Shields ◽  
H. C. Aldrich ◽  
R. L. Carter
Keyword(s):  
Calcium Phosphate ◽  
Cervical Spinal Cord ◽  
Disease Process ◽  
Cervical Vertebra ◽  
Axial Skeleton ◽  
Calcium Pyrophosphate ◽  
Calcium Pyrophosphate Dihydrate ◽  
Appendicular Skeleton ◽  
Canal Stenosis ◽  
Seventh Cervical Vertebra

A new clinicopathologic syndrome, possibly familial, in Great Dane dogs, resembles the familial childhood variant of calcium pyrophosphate dihydrate deposit disease in man, except that the mineral deposits were composed of amorphous calcium phosphate or hydroxyapatite rather than pyrophosphate. The syndrome was characterized clinically by paraplegia and incoordination in very young puppies which was caused by concentric constriction of the posterior cervical spinal cord. Canal stenosis resulted from dorsal displacement of the seventh cervical vertebra and deformation of the vertebral articular processes. Mineral deposition in the diarthrodial joints of the axial skeleton could be seen on radiographs of weanling puppies, and the appendicular skeleton became involved as the dogs matured. Periarticular mineralization of the limbs was associated with shorter bones, a thin cortex, abnormal bone curvature, and increased medullary trabeculae. Bone alterations were associated with abnormalities of the growth plate, which had focal areas of cartilage calcification. Soft tissue mineralization, seen in all dogs, was a primary feature of the disease process. Serum calcium concentrations were within the normal range, but serum phosphorus concentrations were decreased.

scholarly journals Inhibition of hydroxyapatite formation in collagen gels by chondroitin sulphate

1985 ◽  
Vol 228 (2) ◽  
pp. 463-469 ◽  
Author(s):  
G K Hunter ◽  
B L Allen ◽  
M D Grynpas ◽  
P T Cheng
Keyword(s):  
Type I Collagen ◽  
Chondroitin Sulphate ◽  
Collagen Gel ◽  
Calcium Pyrophosphate ◽  
Molar Ratio ◽  
Crystal Formation ◽  
Type I ◽  
Collagen Gels ◽  
High Concentrations ◽  
Hydroxyapatite Formation

Crystal growth in native collagen gels has been used to determine the role of extracellular matrix macromolecules in biological calcification phenomena. In this system, type I collagen gels containing sodium phosphate and buffered at pH 7.4 are overlayed with a solution containing CaCl2. Crystals form in the collagen gel adjacent to the gel-solution interface. Conditions were determined which permit the growth of crystals of hydroxyapatite [Ca10(PO4)6(OH)2]. At a Ca/P molar ratio of 2:1, the minimum concentrations of calcium and phosphate necessary for precipitation of hydroxyapatite are 10 mM and 5 mM, respectively. Under these conditions, precipitation is initiated at 18-24h, and is maximal between 24h and 6 days. Addition of high concentrations of chondroitin 4-sulphate inhibits the formation of hydroxyapatite in collagen gels; initiation of precipitation is delayed, and the final (equilibrium) amount of precipitation is decreased. Inhibition of hydroxyapatite formation requires concentrations of chondroitin sulphate higher than those required to inhibit calcium pyrophosphate crystal formation.

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