On influence of anodic oxidation on thrombogenicity and bioactivity of the Ti-13Nb-13Zr alloy.

PURPOSE: This paper reports on the results of investigations on the blood response to the modified of surfaces titanium alloys.

METHODS: To enhance biocompatibility of the Ti-13Nb-13Zr alloy, anodisation was performed at 80 and 150 V. The oxidation process was carried out in a solution containing 4 mol dm-3 H3PO4 and 0.59 mol dm-3 Ca(H2PO2)2.

RESULTS: The haemolytic activity of the titanium alloy surface was not altered much by the anodisation. The obtained values of the percentage of haemolysis were well below the levels required for the materials intended for blood contact. The clotting time of the blood was similar for the as-ground sample and the sample anodised at 80 V. For the sample anodised at 150 V the clotting time was shorter. The differences between these samples were observed in partial thromboplastin time after activation, prothrombin time and thrombin time, after 24 h. Extracts taken from the samples were not toxic towards the L-929 mouse fibroblast cells.

CONCLUSIONS: The proposed treatment might be appropriate for the preparation of modified Ti-13Nb-13Zr surfaces intended for bone reconstruction or cardiovascular implants depending on process parameters.