engleski

THE MODIFICATION OF BIOLOGICAL PROPERTIES OF TITANIUM FOR BIOMEDICAL APPLICATION

The major issue in clinical orthopaedics is a large bone loss caused by trauma or diseases. Titanium (Ti) and its alloys are widely used as hard tissue replacements. The most limiting features of titanium are high Young’s modulus and lack of biocompatibility. Such properties result in stress shielding and implant’s inability to bond to the surrounding tissue. One of the promising approaches is modification of titanium by hydroxyapatite (HAp), a bioactive ceramic with mineralogical composition similar to one of the human bone. Powder metallurgy is a simple method to produce Ti/HAp composites ; however, with possible thermal decomposition of hydroxyapatite phase during sintering above 800 °C. With this in mind, in this work Ti/HAp composites have been prepared using titanium hydride as a sintering agent to provide titanium sintering at lower temperatures (800 °C) and to preserve stability of apatite phase. Different HAp amounts were applied in order to investigate its influence on mineralogical composition, microstructure, physical and biological properties of Ti/HAp composites. The XRD analysis indicated thermal stability of HAp during vacuum sintering and slight oxidation of titanium. Higher HAp content resulted in decreased density and higher porosity due to formation of micro- and macro-pores caused by the integration of HAp particles into titanium matix. The bioactivity of Ti/HAp composites performed in simulated body fluid (SBF) by standard in vitro test was increased with higher HAp content. Moreover, good viability of Hek293 cells exposed to materials extracts indicated no cytotoxicity of Ti/HAp composites.

Titanium, hydroxyapatite, cytotoxicity

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