Bassani Paola, Panseri Silvia, Ruffini Andrea, Montesi Monica, Ghetti Martina, Zanotti Claudio, Tampieri Anna, Tuissi Ausonio
Unit of Lecco, Institute for Energetics and Interphases, National Research Council of Italy - IENI-CNR, Corso Promessi Sposi 29, 23900, Lecco, Italy,
J Mater Sci Mater Med. 2014 Oct;25(10):2277-85. doi: 10.1007/s10856-014-5253-x. Epub 2014 Jun 14.
Shape memory alloys based on NiTi have found their main applications in manufacturing of new biomedical devices mainly in surgery tools, stents and orthopedics. Porous NiTi can exhibit an engineering elastic modulus comparable to that of cortical bone (12-17 GPa). This condition, combined with proper pore size, allows good osteointegration. Open cells porous NiTi was produced by self propagating high temperature synthesis (SHS), starting from Ni and Ti mixed powders. The main NiTi phase is formed during SHS together with other Ni-Ti compounds. The biocompatibility of such material was investigated by single culture experiment and ionic release on small specimen. In particular, NiTi and porous NiTi were evaluated together with elemental Ti and Ni reference metals and the two intermetallic TiNi3, Ti2Ni phases. This approach permitted to clearly identify the influence of secondary phases in porous NiTi materials and relation with Ni-ion release. The results indicated, apart the well-known high toxicity of Ni, also toxicity of TiNi3, whilst phases with higher Ti content showed high biocompatibility. A slightly reduced biocompatibility of porous NiTi was ascribed to combined effect of TiNi3 presence and topography that requires higher effort for the cells to adapt to the surface.
基于镍钛的形状记忆合金已在新型生物医学设备制造中得到主要应用，主要用于手术工具、支架和骨科领域。多孔镍钛的工程弹性模量可与皮质骨（12 - 17吉帕斯卡）相媲美。这种情况与合适的孔径相结合，有利于良好的骨整合。开孔多孔镍钛是通过自蔓延高温合成法（SHS）由镍粉和钛粉混合制备而成。在自蔓延高温合成过程中，主要的镍钛相以及其他镍钛化合物一同形成。通过对小样本进行单培养实验和离子释放实验，研究了这种材料的生物相容性。具体而言，对镍钛和多孔镍钛与元素钛和镍参考金属以及两种金属间化合物TiNi3、Ti2Ni相进行了评估。这种方法能够清晰地确定多孔镍钛材料中次生相的影响以及与镍离子释放的关系。结果表明，除了众所周知的镍的高毒性外，TiNi3也具有毒性，而钛含量较高的相则表现出高生物相容性。多孔镍钛生物相容性略有降低归因于TiNi3的存在以及表面形貌的综合影响，细胞需要付出更多努力来适应这种表面。
