FTIR monitoring of the growth of the carbonate containing apatite layers from simulated and natural body fluids

The aim of this work is to perform such a chemical modification of the impl ant that in vivo conditions on its surface, heterogeneous nucleation of apa tite from the body fluid could be easily induced and then its growth succes sfully performed. The laboratory experiments were carried out with carbon-c arbon biocomposites and carbon needled clothes. The surface of carbon was c oated with the sol-gel silica or calcium silicate layer and then, under phy siological conditions, thermostatically soaked in the synthetic or natural body fluid. Successive steps of the apatite growth were monitored by infrar ed spectroscopy. It was found that the nucleation and growth of carbonate c ontaining apatite took place at the surface and was more effective on silic a-calcium than on silica substrate. The natural body fluid, compared with s ynthetic body fluid much enhanced the apatite precipitation. This observati on supports suggestion that also proteins can act as nucleation centres. (C ) 1999 Elsevier Science B.V. All rights reserved.