钽离子注入对镍钛合金表面生物学性能的影响

镍钛合金血管支架植入后可引发血栓和支架再狭窄,且对损伤的血管内壁无修复作用,需进行表面改性赋予其抗凝血和促内皮化生物学功能。本研究采用等离子体浸没离子注入与沉积(PIII&D)技术将钽(Ta)注入至镍钛合金,研究Ta离子注入对镍钛表面理化特性及生物学性能的影响规律。结果表明,调控Ta离子注入时间,可在镍钛表面分别构建含Ta、Ta/Ta₂O₅、Ta/Ta₂O_5–x/Ta₂O₅三种不同组分的改性层。各种改性样品中,含Ta/Ta₂O_5–x/Ta₂O₅的改性镍钛表面亲水性均更好,可提供更多细胞附着位点,促进人脐静脉内皮细胞早期粘附和铺展,并提高其增殖能力。相比仅含单质Ta的改性镍钛表面,含Ta/Ta₂O_5–x/Ta₂O₅改性镍钛表面的血液相容性更高,血小板粘附数量显著减少,且基本保持...

Biological Property Investigation of Nitinol Surface Implanted with Tantalum

Nitinol vascular stent can trigger thrombosis and restenosis, but lacks the ability to rehabilitate with injury still to the blood vessel wall. Thus, surface modification to the stent is indispensable for nitinol surfaces to realize biological functions of anticoagulation and accelerate endothelialization. Here, tantalum ions were implanted into nitinol surfaces by plasma immersion ion implantation and deposition (PIII&D). Physicochemical and biological characteristics of the modified nitinol surfaces were analyzed. The results show that the Ta, Ta/Ta₂O₅, and Ta/Ta₂O_5-x/Ta₂O₅-containing modified layers are formed on nitinol surfaces with extension of implantation time. Among all samples, the modified surface containing Ta/Ta₂O_5-x/Ta₂O₅ phase possesses better hydrophilicity and provides more sites for cell attachment to promote initial cell adhesion and proliferation. Compared with the solely Ta-bearing surface, the modified surface containing Ta/Ta₂O_5-x/Ta₂O₅ shows superior hemocompatibility, on which fewer adhered platelets are observed, maitaining an inactive and original spherical shape. Besides, the hemolysis rates of all samples are far below the threshold value of 5%, indicating that hemolysis hardly happens. The results indicate that Ta ion implantation modified nitinol stent has a potential application in reducing thrombosis and accelerating endothelialization.