目的 赋予医用钛表面pH响应性的抗菌功能。方法 采用阳极氧化首先在纯钛表面制备二氧化钛纳米管(TNTs)，随后超声沉积聚多巴胺层(PDA)，再通过化学接枝法将没食子酸和银离子的络合物装载在纳米管表面，制备纯钛表面载银二氧化钛纳米管。通过SEM、XRD、FTIR、XPS对涂层的形貌及成分进行分析，并对涂层在不同pH条件下银离子的释放行为及抗菌能力进行评价。结果 TNTs-PDA-Ag样品具有良好的多孔结构，管径缩小至60 nm，实现了银离子的有效装载，表面Ag的原子数分数约为2.9%，C的原子数分数(69.13 %)相对于TNTs-PDA的原子数分数(37.09 %)明显增加。经体外矿化，TNTs-PDA- Ag表面形成了HA(羟基磷灰石)。涂层在不同pH的磷酸盐缓冲溶液中表现出差异性的Ag⁺释放速率，在pH为4.5的环境中浸泡至7 d时，银离子释放速度和释放比例(97.65%)相对于中性条件下均得到明显提高。在抗菌实验中，Ag⁺的释放浓度在5.56~13 μmol/L之间，对大肠杆菌具有明显的抑菌作用。结论 制备的载银二氧化钛纳米管涂层可以有效提高材料的骨生物相容性，具有一定的pH响应性抗菌功能，在医用钛表面有较大的应用潜力。

Titanium and titanium alloys have a wide range of clinical applications in dental implants, bone screws, and artificial hip joints. However, due to their biological inertia and lack of antibacterial properties, excellent osseointegration cannot be achieved after surgery, they are prone to bacterial infection, inflammation, and implant failure. Surface modification can effectively endow it with biological functions such as promoting bone growth, antibacterial and anti-inflammatory. In view of the bacterial infection of the implant, according to the low pH value of the surrounding environment of the infected tissue, the construction of pH-responsive antibacterial function on the surface of the implant has become a research hotspot. In this study, metal-polyphenol network (MPN) was used to graft silver ions in TiO2 (titanium dioxide) nanotubes, and the responsive release of silver ions was achieved by the pH responsiveness of MPN.