Development of titanium wire ropes for implantable stimulation electrode and their evaluation.

以医用生物材料为研究对象，研究了磨损性能及其相关问题，如磨屑形成、离子洗脱、气体表面硬化、细胞与钛粉反应等。(1)植入材料在模拟体液中的磨损性能1。钛材料销-盘磨损试验中，1 mass%乳酸溶液中的离子溶出比Hanks溶液中的离子溶出更显著.由质量损失计算出的磨损量几乎与所检测的生物材料的滑动距离或接触压力保持恒定，而金属离子的洗脱率随着滑动距离的增加而增加. CP钛钉和钛盘进行磨损试验时，磨损量大于α+β钛合金。结果表明，CP Ti钉与盘之间的界面发生了粘着磨损.当使用PSZ或Si_3N_4针和CP钛盘时，磨损量低于其他陶瓷针，洗脱率较高。(2)表面硬化对钛合金耐磨性的影响。采用CO气体进行表面强化，可以降低CP钛和β型Ti-14 Mo-3 Nb-1. 5 Zr合金销盘磨损过程中的质量损失.采用CO气体对CP钛进行表面强化比对β型Ti-14 Mo-3 Nb-1.5Zr合金更有效，这是因为α型CP钛中氧或碳的溶解度远高于β型钛合金。(3)磨损碎屑的体内和体外评价1。钛粉在模拟体液中引起离子洗脱，但在磨损试验中离子洗脱量占总离子洗脱量的比例相对较低.钛离子可降低RAW 264细胞活力，影响SOD活性和TNF-α生成.结果表明，RAw 264细胞能吞噬直径为10 μm的钛粉，表明RAw 264细胞与钛粉之间存在积极的相互作用。

Wear property and related issues such as wear debris formation, ion elution, surface hardening using gas, reaction between cell and titanium powder were investigated using biomaterials for medical applications.(1) Wear properties of implant materials in simulated body fluids1. Ion elution into 1 mass% lactic acid solution during pin-on-disk wear test of titanium materials was more significant than that into Hanks' solution.2. Wear loss calculated from mass loss was almost constant with sliding distance or contact pressure for biomaterials examined, while elution rate of metal ions increased with increasing sliding distance.3. When CP titanium pin and disk were used for wear test, the wear loss was higher than that of α+β titanium alloys. It was suggested that adhesive wear occurred at the interface between CP Ti pin and disk.4. When PSZ or Si_3N_4 pin and CP Ti disk were used, wear loss was lower than that using other ceramic pin, and elution rate was higher.(2) Effect of the surface hardening on wear property of titanium1. Mass loss during pin-on-disk wear test for CP titanium or β-type Ti-14Mo-3Nb-1.5Zr alloy was decreased by surface hardening using CO gas.2. The surface hardening using CO gas for CP titanium was more effective than that for β-type Ti-14Mo-3Nb-1.5Zr alloy, because solubility of oxygen or carbon in CP titanium with α type structure was much higher than in β-type titanium alloys.(3) In vivo and in vitro evaluation of wear debris1. Titanium powder caused the ion elution in simulated body fluids, but the ion elution is relatively low in total ion elution during wear test.2. RAW 264 cell viability was decreased by titanium ion, and the titanium ion affected the SOD activity and TNF-α formation.3. It was observed that RAw264 cells phagocytosed titanium powder with 10 μm in diameter, which suggested the active interaction between the cell and titanium powder.