Bioactive ceramics

Kim, H.M. (2003) Ceramic bioactivity and related biomimetic strategy. Curr. Opin. Solid State Mater. Res., 7, 289 - 299. 

Bioactive ceramics Bioactive (grows into the bone, etc.), biocompatible Replacement/repair of bones/joints... 

In microsphere sintering, pre-synthesized polymer microspheres or polymer/ceramic/bioactive addiction composites are sintered to produce a 3-D porous scaffold (56). Bioactive scaffolds can be fabricated through this technique, and they are demonstrated to be supportive to human osteoblast-like cells adhesion, growth, and mineralization (57). Scaffolds fabricated through this technique can have graded porosity structures. Mechanical properties close to cancellous bone also become possible when the microspheres are sintered into... 

In their 2006 review, Boccaccini et al. [78] elaborated on the study of combinations of many biodegradable polymer matrices reinforced with inorganic ceramics, bioactive glasses and glass-ceramics, and calcium phosphates as scaffolds for bone tissue engineering applications. 

Phospha.tes. Many phosphates cl aim unique material advantages over siUcates that make them worth the higher material costs for certain apphcations. Glass-ceramics containing the calcium orthophosphate apatite, for example, have demonstrated good biocompatibiUty and, in some cases even bioactivity (the abiUty to bond with bone) (25). Recent combinations of fluorapatite with phlogopite mica provide bioactivity as well as machinability and show promise as surgical implants (26). 

W. Vogel and co-workers, in T. Yamamuro, L. L. Hench, and J. Wilson, eds.. Handbook of Bioactive Ceramics, Hoi 1, Bioactive Glasses and Glass-Ceramics, CRC Press, Boca Raton, Fla., 1990. 

Zinc phosphate, Zn2(P0 2> forms the basis of a group of dental cements. Chromium and zinc phosphates are utilized in some metal-treating appHcations to provide corrosion protection and improved paint adhesion. Cobalt(II) phosphate octahydrate [10294-50-5] Co2(P0 2 8H20, is a lavender-colored substance used as a pigment in certain paints and ceramics. Copper phosphates exhibit bioactivity and are used as insecticides and fungicides. Zinc, lead, and silver phosphates are utilized in the production of specialty glasses. The phosphate salts of heavy metals such as Pb, Cr, and Cu, are extremely water insoluble. 

The so-called bioactive ceramics have been attractive because they spontaneously bond to living bone, however, they are much more brittle and much less flexible than natural bone. Previous studies reported that the essential condition for ceramics to show bioactivity is formation of a biologically active carbonate-containing apatite on their surfaces after exposure to the body fluid [337]. Calciiun sulfate was also used [338]. 

Kokubo, T. (1990) Surface chemistry of bioactive glass-ceramics. Journal of Non-Crystalline Solids, 120, 138-151. 

The combination of bioactive ceramic particles and a polymer matrix gives bioactive materials which show mechanical properties analogous to those of human cortical bone. However, the bioactivity is not so high because the filler content is limited due to the brittleness, and the weak bonding between the filler and matrix may induce problems. 

Bioactive ceramics have already played an important role in bone repair in the clinical fields because of their ability to bond to living bone. However, the use of these bioactive ceramics is limited because of their brittleness and higher Young s modulus than bone. The combination of ceramic and organic components provides us with a design for novel tissue-repairing materials. The establishment of these techniques promises a novel bone repairing material. 

Kokubo, T. (1991) Bioactive glass ceramics Properties and applications. Biomaterials, 12, 155-163. 

Kokubo, T., Ito, S., Huang, Z.T., Hayashi, T., Sakka, S., Kitsugi, T. and Yamamuro, T. (1990) Ca, P-rich layer formed on high-strength bioactive glass-ceramic A-W. Journal of Biomedical Materials Research, 24, 331-343. 

Mori, A., Ohtsuki, C., Sugino, A., Kuramoto, K., Miyazaki, T., Tanihara, M. and Osaka, A. (2003)Bioactive PMMA-based bone cement modified with methacryloxypropyltrimethoxysilane and calcium salts — Effects of calcium salts on apatite-forming ability. Journal of the Ceramic Society of Japan, 111, 738-742. 

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