Gu Y W, Li H, Tay B Y, Lim C S, Yong M S, Khor K A
Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, Singapore 638075, Singapore.
J Biomed Mater Res A. 2006 Aug;78(2):316-23. doi: 10.1002/jbm.a.30743.
Porous NiTi with an average porosity of 55 vol % and a general pore size of 100-600 microm was synthesized by self-propagating high temperature synthesis (SHS) with the addition of mechanically alloyed nanocrystalline Ni-Ti as the reaction agent. The SHS of porous NiTi using elemental powders was also performed for comparison. To enhance the bioactivity of the metal surface, porous NiTi synthesized by nanocrystalline Ni-Ti was subjected to chemical treatment to form a layer of TiO(2) coating. The porous NiTi with TiO(2) coating was subsequently immersed in a simulated body fluid (SBF) to investigate its apatite forming ability. The effects of the addition of nanocrystalline Ni-Ti as reaction agent and the application of apatite coating on osteoblastic behavior were studied in primary cultures of human osteoblast cells. Results showed that the main phases in porous NiTi synthesized by elemental powders were NiTi, Ti(2)Ni, and unreacted free Ni. By using nanocrystalline Ni-Ti as reaction agent, the secondary intermetallic phase of Ti(2)Ni was significantly reduced and the free Ni was eliminated. TiO(2) coating with anatase phase was formed on the surface of porous NiTi after the chemical treatment. A layer consisting of nanocrystalline carbonate-containing apatite was formed on the surface of TiO(2) coating after soaking in SBF. The preliminary cell culture studies showed that the porous NiTi synthesized with the addition of nanocrystalline Ni-Ti attracted marked attachment and proliferation of the osteoblast cells. This gives the evidence of the potential biomedical applications of the porous NiTi.
通过自蔓延高温合成法（SHS），添加机械合金化的纳米晶Ni-Ti作为反应剂，合成了平均孔隙率为55体积%、一般孔径为100 - 600微米的多孔NiTi。还进行了使用元素粉末的多孔NiTi的SHS以作比较。为提高金属表面的生物活性，对通过纳米晶Ni-Ti合成的多孔NiTi进行化学处理以形成TiO₂涂层。随后将带有TiO₂涂层的多孔NiTi浸入模拟体液（SBF）中以研究其磷灰石形成能力。在人成骨细胞的原代培养中研究了添加纳米晶Ni-Ti作为反应剂以及磷灰石涂层的应用对成骨细胞行为的影响。结果表明，由元素粉末合成的多孔NiTi中的主要相为NiTi、Ti₂Ni和未反应的游离Ni。通过使用纳米晶Ni-Ti作为反应剂，Ti₂Ni的二次金属间相显著减少且游离Ni被消除。化学处理后，在多孔NiTi表面形成了具有锐钛矿相的TiO₂涂层。浸泡在SBF中后，在TiO₂涂层表面形成了一层由含纳米晶碳酸盐的磷灰石组成的层。初步的细胞培养研究表明，添加纳米晶Ni-Ti合成的多孔NiTi吸引了成骨细胞的显著附着和增殖。这为多孔NiTi潜在的生物医学应用提供了证据。
