多孔钛合金表面生物活性镁涂层改性及其成骨效应研究

Due to its good biocompatibility, mechanical property and characteristics of bone ingrowth, porous titanium alloy become an ideal material for bone replacement and restoration. However, there are also some defects, such as no bioactivity，poor bone ingrowth to the deep place and the unknown vascularization. How to overcome the above shortcomings becomes our focus in this research plan. Magnesium is a revolutionary biodegradable metallic materials which possess multiple biological effects, such as bone conduction, vein induction and anti-infection. But poor corrosion resistance and insufficient mechanical strength limits its application in the field of bone repair. In this project, based on our early study on the porous titanium alloy, the magnesium coating will be prepared by chemical vapor deposition onto the porous titanium alloy. Then, the Micro arc oxidation will be introduced to adjust the degradation rates for the magnesium. The composite material could integrate the mechanical property of titanium alloy and bioactivity of magnesium, which could induct bone and blood vessels to grow into porous structure, promote osseointegration at the interface and reduce implant-related infection. Thus, the porous titanium alloy could be endued with multiple biological effects. After retrieval, no similar design and report could be found at home and abroad. In this study, through experiment on bone defect repair animal models, we mainly focus on the effects and mechanisms on the new bone formation and the vascular ingrowth to this composite materials, while the anti-infective effects will be in preliminary exploration. We hope to provide an ideal new materials for bone repair and reconstruction.

多孔钛合金材料凭借良好的生物相容性、力学特性和骨长入特性成为骨组织替代修复的理想材料，但仍存在无生物活性、深部骨长入不佳和血管生成情况不明等诸多问题。如何对上述缺点加以改进成为多孔钛合金应用领域研究的重点。镁是一种革命性的可降解金属材料，具有促进骨生长、血管诱导和抗感染等多重生物学作用，但抗腐蚀性差、力学强度不足限制了其在骨修复领域的应用。本项目拟在前期多孔钛合金研究的基础上，采用气相沉积的方法将镁涂层制备于多孔钛合金表面及内部，并用微弧氧化的方法对镁涂层的降解速率加以调控，使该复合材料兼具钛合金力学性能和镁金属生物学活性的优势，诱导新骨和血管长入多孔结构，促进界面骨整合。经检索，国内外未见同类设计与报道。本课题通过动物骨缺损模型修复实验，主要聚焦于复合材料对新骨形成及血管长入的影响及其相关机制研究，同时对镁降解形成的抗感染效果展开初步探索，有望为骨修复重建提供理想新材料。

多孔钛合金材料凭借良好的生物相容性、力学特性和骨长入特性成为骨组织替代修复的理想材料，但仍存在无生物活性、深部骨长入不佳和血管生成情况不明等诸多问题。如何对上述缺点加以改进成为多孔钛合金应用领域研究的重点。镁是一种革命性的可降解金属材料，具有促进骨生长、血管诱导和抗感染等多重生物学作用，但抗腐蚀性差、力学强度不足限制了其在骨修复领域的应用。本项目在前期多孔钛合金研究的基础上，采用真空离子镀膜的方法将镁涂层制备于多孔钛合金表面及内部，使该复合材料兼具钛合金力学性能和镁金属生物学活性的优势，诱导新骨和血管长入多孔结构，促进界面骨整合。通过检测制备的涂层具有良好的粒径和很好的涂层粘附。表面化学成分和形貌分别采用X射线衍射和带有激光能谱的扫描电镜进行分析。体外细胞毒性和增殖实验发现钛合金表面镁涂层对于MC3T3-E1细胞具有良好的生物相容性和可降解性。更进一步的体内研究，包括荧光标记，显微CT扫描分析，VG组织学切片染色等实验发现，多孔钛合金镁涂层修饰后能够显著促进兔股骨髁部缺损在4周和8周时的骨修复，比单纯钛合金组具有更好的骨形成和骨整合。因此，多孔钛合金表面生物活性镁涂层修饰可被用于骨植入物，能够有效促进骨形成和骨整合。