Titanium alloys, whose physical properties are most similar to bone tissue, facilitate the manufacture of high-quality grafts that can effectively repair damaged bones. Titanium is one of the most common materials for bone grafts, but it has serious drawbacks. Its elasticity, hardness and other physical and mechanical parameters greatly exceed those of bone tissue. In many cases, this results in the implant being subjected to too little mechanical load to protect the bone area, causing it to gradually degenerate. To compensate for this material's shortcomings, the researchers studied a series of Ti-Nb alloys and their nanostructure mechanisms on their surfaces.
In the study of soft niobium titanium alloys with niobium content ranging from 5 percent to 50 percent, titanium alloys with 25 percent niobium showed the highest cell activity, said Roman Chernozim, an engineer at the Physical Materials Science and Composites Research Center.
He explained that by making titanium oxide nanotubes on the surface of the implant, the survival rate of the implant could be improved. Titanium oxide nanotubes can improve tissue proliferation and adhesion of cells to metal surface. With the increase of Nb content, the formation of oxide nanotubes on the surface of titanium alloy accelerates. Nanotubes grown by electrochemical anodization, due to their hollow structure, can be loaded onto the implant surface before surgery for local drug delivery, such as antibiotics or growth factors.
By varying the parameters of niobium content and electrochemical anodization, the geometrical parameters, physical and mechanical properties of the nanotubes can be controlled to create implants with specific characteristics that best meet the requirements of clinical goals.
