Calcium polyphosphate

Seguin CA et al (2004) Tissue engineered nucleus pulposus tissue formed on a porous calcium polyphosphate substrate. Spine (Phila Pa 1976) 29(12) 1299-1306... 

Condensed (poly) phosphates may exert different effects on calcium utilization than the aforementioned effects of simple (ortho-) phosphates. Polyphosphates have a much greater affinity for calcium than do orthophosphates, and soluble calcium-polyphosphate complexes are readily formed in the gastric and intestinal environments. In addition, polyphosphates must be hydrolyzed by an intestinal alkaline phosphatase (27) prior to absorption. We have found polyphosphates to be incompletely (80.5%) hydrolyzed to orthophosphate during the digestive process in young adult males when calcium intake was low only 56% of a 1 g phosphorus supplement was absorbed from a polyphosphate sources as compared to 71% from an orthophosphate source (5). 

Sodium aluminium phosphate, acidic Sodium aluminium silicate Sodium benzoate Sodium calcium polyphosphate Sodium carbonate Sodium ethyl p-hydroxybenzoate Sodium ferrocyanide Sodium gluconate... 

Calcium polyphosphate, dissociation and chain length, 4 48 Calcyclin, 46 454-456 Californium, 20 111 availability and price, 31 2 isotopes, 2 201 melting point, 31 6 oxidation state, 2 197 physical properties, 31 36 preparation and purification, 31 5, 7, 12, 33 apparatus, 31 34, 35 purity, 31 3 radioactivity, 31 33 vapor pressure, 31 6 Califomium-252, a-decay, 31 28 Californium oxide, metallothermic reduction, 31 7, 33... 

Among condensed phosphate systems with polyvalent cations, the very complicated calcium salts have been much studied and a great number of compounds have been detected, often with several modifications (5, 27, 28, 34, 54, 79, 186, 137, 191, 198, 204, 211, 276, 805, 830). In this system special interest attaches to the occurrence of crystalline cross-linked phosphates (see Section V) and of calcium pentaphosphate, CayiPsOis (see Section IV,D,/). The end-product obtained by heating Ca(H2P04)2 in the free atmosphere is the high-molecular calcium polyphosphate, which crystallizes in several forms. The condensed strontium phosphates (246, 805) are similarly complicated and cannot readily be made the subject of a brief review. 

Dependence of the Negative Logarithms of the Dissociation Constants of Calcium Polyphosphates on the Anion Chain Lengths and the Ionic Strengths of the Solutions... 

The important bacterial storage material poly-hydroxybutyric acid is related metabolically and structurally to the lipids. This highly reduced polymer is made up of D-(3-hydroxybutyric acid units in ester linkage, about 1500 residues being present per chain. The structure is that of a compact right-handed coil with a twofold screw axis and a pitch of 0.60 nm.a Within bacteria it often occurs in thin lamellae 5.0 nm thick. Since a chain of 1500 residues stretches to 440 nm, there must be 88 folds in a single chain. Present in both cytoplasmic granules and in membranes,b polyhydroxybutyrate can account for as much as 50% of the total carbon of some bacterial In E. coli and many other bacteria polyhydroxybutyrate is present in a lower molecular mass form bound to calcium polyphosphates, proteins, or other macromolecules.d e It has also been extracted from bovine serum albumin and may be ubiquitous in both eukaryotes and prokaryotes.d/e The polymer may function in formation of Ca2+ channels in membranes.b/d... 

Calcium polyphosphates of a metaphosphate composition [Ca(P03)2]n have properties and molecular structures which should yield a substance which is refractory in most environments but is rapidly degraded in systems containing active enzymes. None of the known systems of calcium phosphates yield fibrous crystals, although very short acicular crystals have been grown. (2 )... 

The calcium polyphosphate fibers are very very slowly dissolved in water. Even in boiling 0.1N HC1 the fibers are resistant to degradation, but the fibers are not as resistant to boiling 0.1N NaOH solutions. See Figure 2. 

Chrysotile asbestos is decomposed at temperatures below 500°C. Calcium polyphosphate fibers do not melt at temperatures below 970°C, but the P-phase phosphate is converted to a-phase phosphate at 940°C. 

It is concluded that calcium polyphosphate fibers are viable candidates as safe replacements for asbestos in many of its applications, particularly in those applications where human exposure is considered hazardous. 

Calcium PolyP fibre has been synthesized (Griffith, 1992) and new high-performance calcium polyphosphate bioceramics has been proposed as a bone-substitute material (Nelson et al, 1993 Pilliar et al, 2001). The in vivo experiments, in which porous rods of calcium PolyP were implanted in the distal femur of rabbits, show that these rods can support bone ingrowth and give no adverse reaction (Grynpas et al, 2002). 

Some allowed food additives, for example, E-451 and F-452, contain the following PolyPs triphosphates - pentasodium triphosphate and pentapotassium triphosphate polyphosphates - sodium polyphosphate, potassium polyphosphates and calcium polyphosphate. 

M. D. Grynpas, R. M. Pilliar, R. A. Kandel, R. Renlund, M. Filiaggi and M. Dumitriu (2002). Porous calcium polyphosphate scaffolds for bone substitute applications in in vivo studies. Biomaterials, 23, 2063-2070. 

R. P. Huang, and R. N. Reusch (1995). Genetic competence in Escherichia coli requires poly-beta-hydroxybutirate calcium polyphosphate membrane complex and certain divalent cations. J. 

R. N. Reusch (1989). Poly-beta-hydroxybutirate/calcium polyphosphate complexes in eukaryotic membranes. Roc. Soc. Exper. Biol. Med.., 191, 377-381. 

R. N. Reusch and H. L. Sadoff (1988). Putative structure and functions of poly-beta-hydroxybutirate/calcium polyphosphate channel in bacterial plasma membranes, Proc. Natl. 

Z. Y. Sun and L. Zhao (2002). Feasibility of calcium polyphosphate fiber as scaffold materials for... 

Calcium polyphosphate fibers were grown from a water soluble melt. The raw materials used were lime (CaO) and phosphoric acid (HjPO ) to give... 

Calcium polyphosphate fibers were grown as dendritic spherulites. Sodium calcium polyphosphates were grown as simple crystals and then milled. 

Cross-linked potassium Kurrol s is prepared in exactly the same manner as the calcium polyphosphate fibers. The only difference is potassium is substituted for calcium in the preparation of potassium Kurrol s salt. There is strong reason to question whether or not the strange solution behavior of cross-linked potassium Kurrol s salt is a result of cross-linking in the crystalline phase or is a result of ultra long polyphosphate chains mixed with an independent ultraphosphate phase that contains the required cross-linking. All of the observations which led to the belief that the molecule-ions in the crystalline phase were cross-linked can be explained based upon the two phase model where the ultraphosphate phase is rather quickly degraded in aqueous solutions to form acidic groups. 

To obtain high tensile strengths of calcium polyphosphate fibers crystals it is necessary to grow polyphosphate molecule-ions as long as possible. When a phosphate group from a high temperature melt system moves to a high... 

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