水酸アパタイト溶射皮膜のフレッティング疲労による細胞毒性その場評価

抄録

This study aims to reveal the mechanism of toxicity by experimentally evaluating the cytotoxicity of wear particles which was generated by fretting fatigue under cyclic loading. The super-aging society in Japan lead to the increase in the demand for artificial joints. Titanium alloy is usually used as the material of artificial joints and a hydroxyapatite (HAp) coating is applied to the prostheses surface to improve bone conductivity. However, fretting fatigue due to cyclic loading during walking causes damages such as wear, cracks, and peeling. The wear particles formed by damage can cause an inflammatory response in the body. However, the effect of generated wear particles on cells has not been clarified yet. Although the material used for the test specimens was not toxic, a marked decrease in cell number was observed during the fatigue test, suggesting that toxicity had occurred. The mechanism of promoting toxicity is considered to be the effect of mechanical load and wear particles. Wear particles generated by fretting fatigue caused toxicity to cells which lead to the decrease in cell numbers.