【作者】 刘绪建；

【导师】 宁成云；

【作者基本信息】 华南理工大学 ， 材料学， 2010， 硕士

【摘要】 钛及其合金材料具有良好的机械性能和生物相容性,在口腔和骨修复以及外科矫形种植领域有着广泛的应用。但是,钛作为生物惰性材料,植入人体后很难和宿主骨间形成强有力的化学键合；除此之外,钛表面形成的氧化膜很薄,在生理环境和负载条件下,无法完全阻止种植体向基体材料释放金属离子。这些都严重影响了钛基种植体的临床应用。因此,有必要对钛进行表面改性来完善其生物学性能以适应临床应用。为了促进材料表面的细胞粘附、增殖和分化并且改善组织愈合,本研究首先对纯钛表面进行碱洗处理,再通过采用γ-氨丙基三乙氧基硅烷偶联剂(KH-550)硅烷化改性处理在表面构建过渡层,并体外评价活性过渡层对成骨细胞生物学的影响。为了在钛表面获得富含Ti-OH基团的活性氧化膜,纯钛首先进行了碱处理。处理后借助XRD(X-射线衍射)、XPS(X-光电子能谱)表征表面的化学成分,SEM(扫描电镜)观察钛表面氧化膜的微观形貌。结果显示,碱处理后钛表面为微孔结构,表面为含羟基的二氧化钛层。表明碱热处理后的纯钛表面富含的羟基增加了材料的活性,而且通过钛羟基与硅醇的缩合反应为纯钛材料表面硅烷化提供了可能。纯钛经过碱热预处理以后,本研究通过采用直接浸渍法和冷凝回流法在材料表面共价固定γ-氨丙基三乙氧基硅烷(KH-550),然后通过KH-550的活性氨基基团还可以作为后续实验中固定生物大分子的功能基团,为金属材料的生物化、智能化奠定基础。采用SEM、XPS、EDX(X-射线能谱仪)FT-IR(傅里叶红外光谱仪)等技术及其他现代分析手段对材料进行较为深入系统的研究。通过对体外培养的4-5代HMSCs(入骨髓间质干细胞)在材料表面黏附、增殖及分化的检测,评价材料的细胞相容性。结果显示硅烷化改性纯钛可促进HMSCs向成骨细胞分化,并且促进了细胞的早期黏附,用荧光免疫组化的方法对细胞骨架蛋白观察发现在24h内可使形成良好的铺展形态；倒置荧光显微镜和扫描电镜观察及MTT结果表明硅烷化改性纯钛具有良好的生物相容性,可促进人骨髓间质干细胞在活性层表面的黏附、铺展、增殖和分化。本文通过利用硅烷化改性的方法研究了纯钛材料表面构建活性过渡层的可行性,为钛基金属的表面改性和生物活性设计提供了一种新思路。活性过渡层使材料表面成分更为合理,在分子及细胞水平符合细胞、机体的要求,将可能使材料表面特性在骨整合不同阶段更加优化及合理。更多还原

【Abstract】 Titanium metal and its alloys have been widely used as dental implants, skeletal repair and orthopedic for their superior mechanical properties and good biocompatibility. However, as bio-inert material, it is difficult to form a strong chemical bonding between titanium and host bone after implantation. In addition, the oxidation film on titanium surface is too thin to prevent ion release from matrix under the physical environment and load conditions. These have seriously affected the clinical application of titanium-based implant. Therefore, it is necessary to improve its surface properties to adapt to clinical application.In this paper, the titanium plates were alkali-treatment and modified withy-aminopropyl triethoxysilane coupling agent (KH-550) to form a transition layer on it to improve the adhesion, proliferation and differentiation of cell and the healing of tissue. The biological property of the transition layer was evaluated by in-vitro test.The titanium plates were treated with alkali first to get enough Ti-OH on it. The chemical composition of the specimens were evaluated by XRD and XPS, and the morphology was characterized by SEM. It shows that there is pores structure on titanium surface after alkali-treatment, and there is a layer of TiO2 containing Ti-OH. It illustrated that the activity of the titanium was improved after alkali-treatment, and it provides the possibility to get silane surface of titanium by the condensation reaction of Ti-OH and Si-OH.They-aminopropyl triethoxysilane coupling agent (KH-550) was prepared on the titanium surface after alkali-treatment by direct impregnation and reflux condensation method. Then, the -NH2 on KH-550 could be used to bond functional groups of biological macromolecules to form bioactive and intelligent surface on metal. A in-depth research specimens properties was processed by SEM, XPS, EDX and FT-IR.The HMSCs (generation 4 to 5) were cultured on the surface of the specimens, and the biocompatibility of the specimens was evaluated by the adhesion, proliferation and differentiation of the HMSCs. It shows that the silane surface could improve the adhesion of the cells on early stage, and promote the differentiation of the HMSCs to osteoblast. The cytoskeletal protein was observed by the fluorescent immunohistochemistry method, and the result shows that the cells have a well spread on silane surface. The results of inversion fulorescence microscope, scanning electron microscopy and MTT test show that the silane titanium has good biocompatibility, and could promote the adhesion, spread, proliferation and differentiation of HMSCs. The saline titanium surface were prepared to form a transition layer in this paper, and it provide a new idea to improve the bioactivity of the titanium implantation. The transition layer made the components of the surface more reasonable at the level of molecular and cell, and maybe optimize the property of the materials surface at different stages of osseointegration.更多还原