Enhanced in vitro biocompatibility of ultrafine-grained biomedical NiTi alloy with microporous surface
Enhanced in vitro biocompatibility of ultrafine-grained biomedical NiTi alloy with microporous surface
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DOI：
10.1016/j.apsusc.2011.05.105
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发表时间：
2011-08
影响因子：
6.7
通讯作者：
C. Zheng;F. Nie;Yufeng Zheng;Yan Cheng;Shicheng Wei;R. Valiev
中科院分区：
文献类型：
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作者：
C. Zheng;F. Nie;Yufeng Zheng;Yan Cheng;Shicheng Wei;R. Valiev
采用等通道转角挤压（ECAP）技术制备了块体超细晶Ni 50. 8 Ti49. 2合金（UFG-NiTi），并采用喷砂、酸蚀和碱处理等表面改性技术制备了具有生物活性的不规则粗糙表面、微孔表面和分级多孔表面，以进一步提高其表面的生物相容性。以粗晶NiTi合金为对照，系统研究了上述表面处理工艺对UFG-NiTi合金表面粗糙度、润湿性、腐蚀行为、离子释放、磷灰石形成能力和细胞相容性的影响。在HF/HNO 3溶液中，喷砂处理使点蚀电位（Epit）从393 mV（SCE）提高到704 mV（SCE），酸蚀处理使点蚀电位进一步提高到1539 mV（SCE）。上述表面处理均不同程度地提高了UFG-NiTi在模拟体液（SBF）中的磷灰石形成能力。同时，喷砂和酸蚀处理均能促进成骨细胞的细胞相容性：喷砂处理促进细胞贴壁，酸蚀处理促进细胞增殖。不同表面改性后的UFG-NiTi的腐蚀行为、磷灰石形成能力和细胞反应的不同归因于所得表面氧化层的形貌和润湿性。
Bulk ultrafine-grained Ni50.8Ti49.2alloy (UFG-NiTi) was successfully fabricated by equal-channel angular pressing (ECAP) technique in the present study, and to further improve its surface biocompatibility, surface modification techniques including sandblasting, acid etching and alkali treatment were employed to produce either irregularly roughened surface or microporous surface or hierarchical porous surface with bioactivity. The effect of the above surface treatments on the surface roughness, wettability, corrosion behavior, ion release, apatite forming ability and cytocompatibility of UFG-NiTi alloy were systematically investigated with the coarse-grained NiTi alloy as control. The pitting corrosion potential (Epit) was increased from 393 mV (SCE) to 704 mV (SCE) with sandblasting and further increased to 1539 mV (SCE) with following acid etching in HF/HNO3solution. All the above surface treatment increased the apatite forming ability of UFG-NiTi in varying degrees when soaked them in simulated body fluid (SBF). Meanwhile, both sandblasting and acid etching could promote the cytocompatibility for osteoblasts: sandblasting enhanced cell attachment and acid etching increased cell proliferation. The different corrosion behavior, apatite forming ability and cellular response of UFG-NiTi after different surface modifications are attributed to the topography and wettability of the resulting surface oxide layer.