A NiTi shape memory alloy （SMA） modified by Ta ion implantation was subjected to oxidation treatment in air at 723 and 873 K. Atomic force microscopy （AFM）, Auger electron spectroscopy （AES）, and grazing inciden...A NiTi shape memory alloy （SMA） modified by Ta ion implantation was subjected to oxidation treatment in air at 723 and 873 K. Atomic force microscopy （AFM）, Auger electron spectroscopy （AES）, and grazing incidence X-ray diffraction （GIXRD） measurements were conducted to investigate the surface characteristics, including surface topography, elemental depth profiles, and surface phase structures. The surface roughness of the Ta-implanted NiTi increases after oxidation, and the higher the oxidation temperature is, the larger the value is. The surface of the Ta-implanted NiTi oxidized at 723 K is a nanolayer mainly composed of TiO2/Ta2O5 and TiO with depressed Ni content. The Ta-implanted NiTi oxidized at 873 K is mainly covered by rutile TiO2 in several micrometers of thickness. Potentiodynamic polarization tests indicated that the corrosion resistance of the Ta-implanted NiTi was improved after thermal oxidation at 723 K, but a negative impact was found for the Ta-implanted NiTi oxidized at 873 K.展开更多
To protect the surface of NiTi from corrosion, an ion implantation method was proposed. In the present work, a surface oxidized sample was implanted with nitrogen at energy of 100 keV. The corrosion resistarwe propert...To protect the surface of NiTi from corrosion, an ion implantation method was proposed. In the present work, a surface oxidized sample was implanted with nitrogen at energy of 100 keV. The corrosion resistarwe property was examined by the anodic polarization method in a simulated body fluid （SBF） at a temperature of 37 ℃ and contrasted to non-implanted NiTi samples. The composition and structure of the implanted layers were investigated by XPS. The experimental results from the electrochemical measurements provide an evidence that the nitrogen ion-implantation increases the corrosion resistance of NiTi shape memory alloy.展开更多
The influence of different surface coatings of NiTi shape memory allays was examined using in vitro testing methods. Plates of superelastic nickel-titanium shape memory allay （ NiTi ） were coated with calcium phosph...The influence of different surface coatings of NiTi shape memory allays was examined using in vitro testing methods. Plates of superelastic nickel-titanium shape memory allay （ NiTi ） were coated with calcium phosphates （ hydroxyapatite ） by high-temperature plasma-spraying or by dip-coating. The biocompatibility was tested in vitro by cultivation of isolated human granulocytes and whole blood cells. As substrates, pure NiTi, plasma-spray-coated NiTi and dip-coated NiTi were used. Isolated granulocytes showed an increased adhesion to both calcium phosphate-coated NiTi samples. Compared to non-coated NiTi or dip-coated NiTi, the number of dead granulocytes adherent to plasma-sprayed surfaces was significantly increased （ p 〈 0.01 ）. Whether the d/f- ferences in apoptosis of granulocytes on dip-coated vs plasma-sprayed coatings observed are due to differences in material surface morphologies has to be analyzed in further studies. Because of the cellular interactions with the coating layers, h is likely that the results obtained are not caused by the underlying NiTi but due to the coating itself.展开更多
Ti Ni alloys, with their unique shape memory effects and super elastic properties, occupy an indispensable place in the family of metallic biomaterials. In the past years, surface treatment is the main technique to im...Ti Ni alloys, with their unique shape memory effects and super elastic properties, occupy an indispensable place in the family of metallic biomaterials. In the past years, surface treatment is the main technique to improve the bioinert nature of microcrystalline Ti Ni alloys and inhibit on the release of toxic nickel ions to obtain excellent osteogenesis and osseointegration function. In the present study, nanocrystalline Ti49.2Ni50.8 alloy has been fabricated via equal channel angular pressing(ECAP), and the in vitro and in vivo studies revealed that it had enhanced cell viability, adhesion, proliferation, ALP(Alkaline phosphatase)activity and mineralization, and increased periphery thickness of new bone, in comparison to the commercial coarse-grained counterpart. These findings indicate that the reduction of grain size is beneficial to increasing the biocompatibility of Ti49.2Ni50.8 shape memory alloy.展开更多
目的镍钛形状记忆合金骨植入物临床使用过程中存在镍离子析出的风险,植入物镍离子释放在体内很难直接测试,为此本文建立一种镍钛形状记忆合金骨植入物镍离子释放的体外测试方法。方法选用磷酸盐缓冲盐溶液(phosphate buffer salt soluti...目的镍钛形状记忆合金骨植入物临床使用过程中存在镍离子析出的风险,植入物镍离子释放在体内很难直接测试,为此本文建立一种镍钛形状记忆合金骨植入物镍离子释放的体外测试方法。方法选用磷酸盐缓冲盐溶液(phosphate buffer salt solution,PBS)作为测试液,用于植入物镍离子的浸提,将植入物置于带盖容器中,容器中装有PBS,将容器静置在温度稳定控制的恒温培养箱内(37±1)℃下,静置相应设置的时间点,每个时间点设1组空白试验和3个相同平行试样进行镍释放量测定,分别用石墨炉原子吸收光谱仪(atomic absorption spectrometer,AAS)和电感耦合等离子体质谱仪(inductively coupled plasma mass spectrometry,ICP-MS)设备测试溶液中镍离子浓度。结果随时间推移从器械中释放出来的镍离子浓度整体呈下降趋势,镍离子释放时点为4周时,释放周期结束,AAS测得镍离子释放量平均值为0.37×10^(-3)μg/(cm^(2)·d),累计释放量平均值为10.22×10^(-3)μg/cm^(2)。ICP-MS测得镍离子释放量平均值为0.29×10^(-3)μg/(cm^(2)·d),累计释放量平均值为7.9×10^(-3)μg/cm^(2)。AAS和ICP-MS两种测试方法测试结果差异性不大,结果数据的走势相同说明试验可重复性高。结论此方法可为镍钛形状记忆合金骨植入物的风险评估提供依据,确保植入物在临床使用过程中镍离子的析出不会对人体造成伤害,保证其临床使用的安全性。展开更多
基金supported by the National Natural Science Foundation of China (No.50971007)the Program for New Century Excellent Talents in Universities from the Ministry of Education of China (No.NCET-09-0024)
文摘A NiTi shape memory alloy （SMA） modified by Ta ion implantation was subjected to oxidation treatment in air at 723 and 873 K. Atomic force microscopy （AFM）, Auger electron spectroscopy （AES）, and grazing incidence X-ray diffraction （GIXRD） measurements were conducted to investigate the surface characteristics, including surface topography, elemental depth profiles, and surface phase structures. The surface roughness of the Ta-implanted NiTi increases after oxidation, and the higher the oxidation temperature is, the larger the value is. The surface of the Ta-implanted NiTi oxidized at 723 K is a nanolayer mainly composed of TiO2/Ta2O5 and TiO with depressed Ni content. The Ta-implanted NiTi oxidized at 873 K is mainly covered by rutile TiO2 in several micrometers of thickness. Potentiodynamic polarization tests indicated that the corrosion resistance of the Ta-implanted NiTi was improved after thermal oxidation at 723 K, but a negative impact was found for the Ta-implanted NiTi oxidized at 873 K.
基金Funded by the National Natural Science Foundation of China(20273012 ) and Education Government of Hainan Province(Hjkj200415)
文摘To protect the surface of NiTi from corrosion, an ion implantation method was proposed. In the present work, a surface oxidized sample was implanted with nitrogen at energy of 100 keV. The corrosion resistarwe property was examined by the anodic polarization method in a simulated body fluid （SBF） at a temperature of 37 ℃ and contrasted to non-implanted NiTi samples. The composition and structure of the implanted layers were investigated by XPS. The experimental results from the electrochemical measurements provide an evidence that the nitrogen ion-implantation increases the corrosion resistance of NiTi shape memory alloy.
文摘The influence of different surface coatings of NiTi shape memory allays was examined using in vitro testing methods. Plates of superelastic nickel-titanium shape memory allay （ NiTi ） were coated with calcium phosphates （ hydroxyapatite ） by high-temperature plasma-spraying or by dip-coating. The biocompatibility was tested in vitro by cultivation of isolated human granulocytes and whole blood cells. As substrates, pure NiTi, plasma-spray-coated NiTi and dip-coated NiTi were used. Isolated granulocytes showed an increased adhesion to both calcium phosphate-coated NiTi samples. Compared to non-coated NiTi or dip-coated NiTi, the number of dead granulocytes adherent to plasma-sprayed surfaces was significantly increased （ p 〈 0.01 ）. Whether the d/f- ferences in apoptosis of granulocytes on dip-coated vs plasma-sprayed coatings observed are due to differences in material surface morphologies has to be analyzed in further studies. Because of the cellular interactions with the coating layers, h is likely that the results obtained are not caused by the underlying NiTi but due to the coating itself.
基金supported by the National Key R&D Program of China (No. 2018YFC1106600)National Natural Science Foundation of China (NSFC)+4 种基金the Russian Foundation for Basic Research (RFBR) NSFC-RFBR Cooperative Project (No. 51611130054)the National Natural Science Foundation of China (Nos. 51431002 and 51871004)the National Natural Science Foundation of China (NSFC)the Research Grants Council (RGC) of Hong Kong NSFC-RGC Joint Research Scheme (Grant No. 5161101031)the financial support from Saint Petersburg State University in the framework of Call 3 project (id 26130576)
文摘Ti Ni alloys, with their unique shape memory effects and super elastic properties, occupy an indispensable place in the family of metallic biomaterials. In the past years, surface treatment is the main technique to improve the bioinert nature of microcrystalline Ti Ni alloys and inhibit on the release of toxic nickel ions to obtain excellent osteogenesis and osseointegration function. In the present study, nanocrystalline Ti49.2Ni50.8 alloy has been fabricated via equal channel angular pressing(ECAP), and the in vitro and in vivo studies revealed that it had enhanced cell viability, adhesion, proliferation, ALP(Alkaline phosphatase)activity and mineralization, and increased periphery thickness of new bone, in comparison to the commercial coarse-grained counterpart. These findings indicate that the reduction of grain size is beneficial to increasing the biocompatibility of Ti49.2Ni50.8 shape memory alloy.
文摘目的镍钛形状记忆合金骨植入物临床使用过程中存在镍离子析出的风险,植入物镍离子释放在体内很难直接测试,为此本文建立一种镍钛形状记忆合金骨植入物镍离子释放的体外测试方法。方法选用磷酸盐缓冲盐溶液(phosphate buffer salt solution,PBS)作为测试液,用于植入物镍离子的浸提,将植入物置于带盖容器中,容器中装有PBS,将容器静置在温度稳定控制的恒温培养箱内(37±1)℃下,静置相应设置的时间点,每个时间点设1组空白试验和3个相同平行试样进行镍释放量测定,分别用石墨炉原子吸收光谱仪(atomic absorption spectrometer,AAS)和电感耦合等离子体质谱仪(inductively coupled plasma mass spectrometry,ICP-MS)设备测试溶液中镍离子浓度。结果随时间推移从器械中释放出来的镍离子浓度整体呈下降趋势,镍离子释放时点为4周时,释放周期结束,AAS测得镍离子释放量平均值为0.37×10^(-3)μg/(cm^(2)·d),累计释放量平均值为10.22×10^(-3)μg/cm^(2)。ICP-MS测得镍离子释放量平均值为0.29×10^(-3)μg/(cm^(2)·d),累计释放量平均值为7.9×10^(-3)μg/cm^(2)。AAS和ICP-MS两种测试方法测试结果差异性不大,结果数据的走势相同说明试验可重复性高。结论此方法可为镍钛形状记忆合金骨植入物的风险评估提供依据,确保植入物在临床使用过程中镍离子的析出不会对人体造成伤害,保证其临床使用的安全性。
