Composite materials tricalcium phosphates

Calcium phosphate A family of calcium- and phosphate-containing materials of synthetic or natural origin which are utilized for implants and bone augmentation purposes. The most prominent materials are the tricalcium-phosphate- and hydroxyapatite-based materials, although most synthetic implants are a mixture of the various compositions. 

If a nearly inert material is implanted into the body it initiates a protective response that leads to encapsulation by a nonadherent fibrous coating about 1 i.m thick. Over time this leads to complete isolation of the implant. A similar response occurs when metals and polymers are implanted. In the case of bioactive ceramics a bond forms across the implant-tissue interface that mimics the bodies natural repair process. Bioactive ceramics such as HA can be used in bulk form or as part of a composite or as a coating. Resorbable bioceramics, such as tricalcium phosphate (TCP), actually dissolve in the body and are replaced by the surrounding tissue. It is an important requirement, of course, that the... 

Peter, S. J., Miller, S. T., Zhu, G. M., Yasko, A. W. Mikos, A. G. (1998) In vivo degradation of a poly(propylene fiimarate) beta-tricalcium phosphate injectable composite scaffold. Journal of Biomedical Materials Research, 41, 1-7. 

Calcium-based composites rely on their similarity to the mineral component of natural bone— hydroxyapatite (HA). The theory behind their use is that the body will see these materials as tissues that need to be remodeled, allowing them to be integrated with and then replaced by bone. Tricalcium phosphate [TCP, Ca3(P04)2], calcium sulfate [plaster of paris, CaS04], and hydroxyapatite [Ca,o(P04)s(OH)2] are all currently being used to fill bony deflects and stimulate or direct bone formation. Calcium suifate has been used for over a century due to its ready availability and bio-... 

Lei, Y., Rai, B., Ho, K.H., Teoh, S.H., 2007. In vitro degradation of novel bioactive poly-caprolactone-20% tricalcium phosphate composite scaffolds for bone engineering. Materials Science and Engineering C-Biomimetic and Supramolecular Systems 27, 293-298. 

There are many applications for calcium phosphate bioceramics can be seen in Fig. 7. The form of calcium phosphate used in orthopedic clinical applications is usually based on hydroxyapatite and )8-tricalcium phosphate. The materials are widely used in composite formulations together with ... 

By aqueous dispersion of the triblock copol5uner mixed with different ratios of hydroxyapatite/tricalcium phosphate, a composite gel imderwent a sol-gel-sol transition when the temperature was increased from 4°C to 70°C. The particle size and critical micellization concentration were increased by adding the ceramic materials. 

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