Apatite, biological composition

Poly(oxyethylene)-Si02 ormosils have been prepared as an approach to the preparation of biologically active polymer-apatite composites. For this purpose, Yamamoto et al. [72] obtained these Class II hybrids from triethoxysilyl-terminated poly(oxyethylene) (PEG) and TEOS by using the in situ sol-gel process. After being subjected to the biomimetic process to form the bone-like apatite layer, it was found that a dense apatite layer could be prepared on the hybrid materials, indicating that the silanol groups provide effective sites for CHA nucleation and growth. 

Geochim Cosmochim Acta 60 4811 829 Kohn MJ (1999) Why most dry rocks should cool wet . Am Miner 84 570-580 Kohn MJ, Ceding TE (2002) Stable isotope compositions of biological apatite. Rev Miner Geochem 48 455 88... 

There are multiple applications of fluoridated bioceramics, essentially as bone and tooth substitutes (Table 1), involving bulk ceramics, glasses, composite materials and coatings for medical devices and surface treatments. In some cases, fluoride ions can leach out of the material inducing a direct biological effect in a soluble form. However, considering the affinity of fluoride ions for apatite... 

Ideally, hydroxyapatite has the formula mentioned above. The synthetic material usually contains fewer than 10 Ca-ions and more than 2 OH-ions per crystal unit. Important differences in crystal structure, composition and specific surface exist between synthetic and biologic apatite. These differences result from the processing method of the raw materials and the synthetic method used. 

Kohn MJ, Cerling TE (2002) Stable isotope compositions of biological apatite. Rev Mineral Geochem 48 455-488... 

In practice in biological apatites, it is most likely that both size- and microstrainbroadening are present. Inhomogeneities in the chemical composition of the crystals may also cause broadening of maxima, particularly those maxima whose positions are mainly... 

Pellegrino ED, Biltz RM (1965) The composition of human bone in uremia. Medicine 44 397-418 Penel G, Leroy G, Rey C, Bres, E (1998) MicroRaman spectral study of the PO4 and CO3 vibrational modes in synthetic and biological apatites. Calcif Tissue Inti 63 475-481 Posner AS, Betts F (1975) Synthetic amorphous calcium phosphate and its relation to bone mineral stracture. Accounts ChemRes 8 273-281... 

Stable Isotope Compositions of Biological Apatite REFERENCES... 

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