镍钛形态记忆合金与骨组织相容性的超微结构观察

背景镍钛合金因具有形状记忆效应和高弹性的特性,成为最有应用前景的金属生物医学材料之一.但其表面不具有生物活性,植入后不能与骨整合.目的通过将表层涂有羟基磷灰石多孔修饰层的镍钛合金植入兔股骨,以观察其生物学特性.设计空白对照观察.单位天津医科大学组织胚胎学教研室实验室.对象雄性成年纯系日本白兔24只,随机分为实验组和对照组各12只.方法实验于2001-07/2002-12在天津医科大学组织胚胎学教研室完成.兔24只,选取其左侧股骨下1/3处为种植区,实验组12只动物植入镍钛合金,对照组12只仅手术钻孔,不植入任何材料,作空白对照.分别于术后4,8,16周各组取4只兔左侧股骨种植区标本进行组织学光镜及电镜观察. 主要观察指标兔左侧股骨种植区标本组织学及超微结构观察.结果24只兔均进入结果分析.①兔左侧股骨种植区标本组织学观察结果术后4周,实验组骨膜反应稍重于对照组,术后16周,实验组有许多大片的类骨质,骨板排列较规则,新骨已基本形成;对照组骨板排列十分规则,新骨已完全成熟.②兔左侧股骨种植区标本超微结构观察术后8周,实验组及对照组植入区骨小梁周围有大量成骨细胞,新生的骨板排列规则.术后16周,实验组及对照组哈弗氏系统已成熟,中央管内皮细胞完整,其周围哈弗氏骨板中骨细胞形态良好,细胞较小,细胞器相对较少.结论此镍钛形态记忆合金植入机体后无排斥反应,与骨组织具有很好的相容性.

Ultrastructural observation of the compatibility between NiTi shape memory alloy and bone tissues

BACKGROUND: NiTi alloy, characterized by its shape memory effect and superelasticity, is a metal biomedical material that has a great potential for future application. However, the alloy does not provide good integration between implanted materials and bone tissues due to the fact that it does not have biological activity.OBJECTIVE: To observe the biological characteristics through transplanting the NiTi alloy modified by a bioactive calcium phosphate layer on the surface into the femur of the rabbit.DESIGN: A blank controlled observationSETTING: The Laboratory of Department of Histology and Embryology of Tianjin Medical UniversityMATERIALS: Totally 24 male adult pure Japanese white rabbits were randomized into the experimental group and the control group with 12 rats in each group.METHODS: The experiment was conducted at the Department of Histology and Embryology of Tianjin Medical University between July 2001 and December 2002. 1/3 of left-sided femur was selected as the implanted area, and Niti alloy was implanted into the 12 animals in the experimental group. Holes were made in twelve rabbits of the control group without addition of any materials as the blank control group. Samples of Left-sided femur implanted area of the 4 white rabbits in each group were selected respectively at 4, 8 and 16 weeks after implantation to perform histological optical and electron microscopic observation.MAIN OUTCOME MEASURES: Histological and ultrastructure observation of implanted area sample at the left-sided femur of the rabbits.observation results of the implanted area at the left-side femur of the rabbits: 4 weeks after implantation, periosteum reactionin the experimental group was a little obvious than that in the control group. Sixteen weeks after implantation, many big pieces of osteoid appeared, and bone lamellas were well arranged and the new bone had formed basically; in the control group, bone lamellas were very well arranged, and the new bone were the left-sided femur of the rabbits: 8 weeks after implantation, a lot of osteoblasts appeared around the bone trabecula at the implanted area in the experimental group and control group. And the new bone lamella was well arranged. 16 weeks after implantation, the haversian system in the experimental group and control group had been matured and the central canal endothelial cells were completed , bone morphology in haversian bone lamella around it was good, and cells were small and the organells were relatively reduced.CONCLUSION: The NiTi shape memory alloy possesses an excellent compatibility with bone tissues. It does not display the rejection reaction after it is implanted into the body.