バイオメディカル用Ti-Cu合金の抗菌性と細胞の生体適合性に及ぼす超音波マイクロアーク酸化の影響

Effect of ultrasonic micro-arc oxidation on the antibacterial properties and cell biocompatibility of Ti-Cu alloy for biomedical application.

• Jiali Hu
• Haixia Li
• Xiaoyan Wang
• Lei Yang
• Mian Chen
• Renxian Wang
• Gaowu Qin
• Da-Fu Chen
• Erlin Zhang

抄録

Ti-Cu合金の抗菌性と細胞の生体適合性を向上させるために、超音波マイクロアーク酸化(UMAO)をTi-Cu合金に適用した。UMAOの表面バイオ改質法としての適用可能性を評価するために、電気化学試験,プレートカウント法及びCCK-8試験走査型電子顕微鏡(SEM)技術を用いて、UMAO適用前後のTi-Cu合金の耐食性,抗菌活性及び細胞適合性を詳細に検討した。表面微細構造の特性評価の結果、Ti-Cu合金の表面には、孔径3〜8μm、厚さ5〜15μmの典型的な多孔質コーティングが形成され、表面粗さと親水性が大幅に改善されていることがわかった。また、プレートカウント法により、Ti-Cu合金上のUMAOコーティングは、生理食塩水に20日間浸漬した後でも黄色ブドウ球菌（S. aureus）に対して強い抗菌活性（99%以上）を示し、UMAO処理Ti-Cu合金は非常に強い長期抗菌性を有することが明らかになった。Ti-Cu-UMAO試料の強い長期抗菌特性は、主にUMAO皮膜中にCuOとCuOが形成されたことによるものと考えられる。細胞適合性評価の結果、UMAO処理は細胞毒性をもたらさないが、MC3T3細胞の早期接着性を改善することが示された。

In order to improve antibacterial properties and cell biocompatibility of Ti-Cu alloy, an ultrasonic micro-arc oxidation (UMAO) has been applied to Ti-Cu alloy. The corrosion resistance, antibacterial activity and cell compatibility of Ti-Cu alloy before and after UMAO were studied in detail by means of electrochemical test, plate count method and CCK-8 test scanning electron microscopy (SEM) technology to evaluate the application possibilities of UMAO as a surface bio-modification method for Ti-Cu alloy. The surface microstructure characterisation showed that a typical porous coating with a pore diameter of 3-8 μm and a thickness of 5-15 μm was formed on the surface of the Ti-Cu alloy, which significantly improved the surface roughness and hydrophilicity. The plate count method demonstrated that UMAO coatings on Ti-Cu alloy showed strong antibacterial activity (≥99%) against Staphylococcus aureus (S. aureus) even after being immersed in a physiological saline for up to 20 days, indicating that UMAO-treated Ti-Cu alloy had very strong long-term antibacterial properties. It is believed that the strong long-term antimicrobial properties of Ti-Cu-UMAO samples were mainly due to the formation of CuO and CuO in UMAO coatings. The results of cell compatibility evaluation showed that UMAO treatment did not bring about cytotoxicity but improved the early adhesion of MC3T3 cell.

Copyright © 2020. Published by Elsevier B.V.