How Does Bioactive Ions Perform When Added To Titanium Bar For Medical Application?

Titanium is widely used as a hard tissue repair material in clinical practice. In recent years, the additive manufacturing technology of titanium metal materials has been continuously improved, showing obvious advantages in the rapid production of customized products, and the processing cycle is not affected by the structure, and has objective application prospects in clinical practice.

However, Ti itself is a biologically inert material. On the one hand, it does not have the ability to regulate the immune system of the human body, and it is prone to inflammatory reactions and loosening after implantation in the human body. Therefore, it is necessary to modify the surface of medical titanium rods to improve the quality, improve the compatibility with the human body, and slow down the inflammatory response.

When the titanium alloy is implanted into the surface of the body to prepare the micro-nano composite structure, its biological properties can be enhanced by adding biologically active ions. The micro-nano composite structure containing calcium ions can increase the hydrophilicity and biological activity of the implant, and promote the adhesion, proliferation and differentiation of bone marrow stem cells. Titanium sheets were prepared by laser selective melting technology and acid-etched to remove the Ti particles produced in the production process and expose the micron-scale structure on the surface of the titanium sheets. By anodic oxidation of the acid-etched samples under different electrolyte and voltage conditions, the changes of surface morphology and nanotube size were studied, and the oxidation parameters suitable for subsequent experiments were selected.

Micro-nano composite structures containing calcium and zinc ions were prepared on the surface of SLM titanium alloy by alkali heat treatment and ion replacement. The results show that the diameter of nanotubes decreases slightly after alkali heat treatment, and the surface roughness changes little. Zinc ions can modulate the polarization behavior of macrophages. Finally, the in vivo osteogenic properties of the micro-nano composite structure titanium rod implants containing calcium ions. The titanium rod implants formed by SLM were subjected to acid etching, anodization and alkali heat treatment, and then implanted into the femur of Sprague-Dawley rats. The amount of new bone around the titanium rod was observed by Micro-CT. The results show that the titanium rods with bioactive ions have good osteogenic properties.