Apatite layers

M., Miyazaki, T., Tanihara, M., Sakaguchi, Y. and Konagaya, S. (2004) Coating of an apatite layer on polyamide films containing sulfonic groups by a biomimetic process. Biomaterials, 25, 4529 f534. 

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. 

Rhee, S.H. (2003) Effect of calcium salt content in the poly(e-caprolactone)/ silica nanocomposite on the nudeation and growth behavior of apatite layer. Journal of Biomedical Materials Research, 67A,1131-1138. 

Weng, J., Liu, Q., Wolke, X G. C., Zhang, X., and de Groot, K., Formation and characteristics of the apatite layer on plama-sprayed hydroxyapatite coatings in simulated body fluid. Biomaterials 18 (15), 1027-1035 (1997). 

Protein comprises about 10% by weight of the organic matrix. The proteins are phosphorylated, and are enriched in aspartic acid, glutamic acid and glycine. Some of the proteins and the chitin are intimately associated. The carbonated apatite layer contains much more protein than the magnetite layer [22]. To date, nothing is known about the individual proteins within the framework. 

Hatton, P.V., and James, P.F. (2002) Formation of apatite layers on modified canasite glass-ceramics in simulated body fluid. / Biomed. Mater. Res., 59 (3), 473 -480. 

Oliveira, A.L., Costa, S.A., Sousa, R.A., and Reis, R.L. (2009) Nucleation and growth of biomimetic apatite layers on 3D plotted biodegradable polymeric scaffolds effect of static and dynamic coating conditions. Acta Biomater., 5 (5), 1626-1638. 

Hence in coatings incubated for only up to 28 days the newly formed layer of secondary hydroxyapatite is decoupled from the stress state of the original layer showing essentially zero stress. Increasing the incubation time may also increase the compressive stress state again caused by reorganisation, consolidation and densification of the biomimetically precipitated Ca-deficient bone-like apatite layer (Gotze etal., 2001). 

Bioactivity is determined by the ability of a material to invoke a crystallized carbonated apatite layer from a physiological fluid. Silica incorporation in HAp promotes early crystallization and a higher rate of osteoblastic cell proliferation on sintered materials. This response has not been isolated from the effects of different Ca/P ratio, surface area, and presence of other calcium phosphate phases (Best et al. 1997). Such comparative information on the influence of different substituent elements on the bioactivity still remains to be developed. In assessing the cell growth on apatites, it is... 

Figure 11. Precipitate formed on a plasma-sprayed coating exhibiting the small crystallite size associated with the newly deposited apatite layer.

Hata K, Kokubo T, Nakamura T, Yamamuro T (1995) Growth of a bonelike apatite layer on a substrate by a biomimetic process. J Am Ceram Soc 78(4) 1049-1053 Hatton T, Iwadate Y, Inai H, Sato K, Imai Y (1987) Preparation of hydroxylapatite powder using a freeze-diying method. J Ceram Soc Japan 95 825-827... 

Weng J, Liu W, Wolke JGC, Zhang XD, de Groot K (1997) Formation and characteristics of the apatite layer on plasma-sprayed hydroxylapatite coatings in simulated body fluid. Biomaterials 18 1027-1035 Weng W, Baptista JL (1998) Alkoxide route for preparing hydroxylapatite and its coatings. Biomaterials 19 125-131... 

MC 3T3-E1 cells on the apatite layer, as formed on the two kinds of scaffolds... 

T. Kokubo, F. Miyaji, H. M. Kim, and T. Nakamura, Spontaneous Formation of Bone-like Apatite Layer on Chemically Treated Titanium Metals, J. Am. Ceram. Soc., 70,1127-9 (1996). 

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