Apatite formation on cobalt and titanium alloys by a biomimetic process
Biomimetic processes mimic the bodies own bone formation and deposition processes. The biomimetic process can be used impart bioactive characteristics onto otherwise bioinert biocompatible materials through the deposition of a bone-like apatite layer. This means that, when implanted, the human body more finds it more difficult to distinguish the implant as a foreign object, hence reducing the chance if rejection.
For implants in orthopedics or dental applications, such as hip and maxillae facial prostheses, which are typically made of titanium or cobalt alloys the apatite layer deposited on the surface of the implant will increase the rate at which bone bonds to them. Similar behavior is common for other implant materials such as tantalum, alumina, and biodegradable polymer composites.
Excellent results are being achieved with a new biomimetic process that involves immersion in simulated body fluid (SBF). This leads to the spontaneous formation of a bone-like apatite layer on the alloy. However, the apatite formation mechanism is not yet fully understood.
This work, published in AZojomo*, by researchers J. C. Escobedo Bocardo, M. A. López Heredia, D. A. Cortés Hernández, A. Medina Ramírez and J. M. Almanza Robles from Centro de Investigación y de Estudios Avanzados – Instituto Politécnico Nacional presents the comparative results of the effect of the SBF concentration on the apatite formation between titanium and cobalt alloys.
They found the process to be more effective on the titanium alloys than results for cobalt alloy samples at all SBF concentrations. The researchers also found higher SBF concentrations resulted in thicker apatite layers and faster growth rates.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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