【作者】 陶涛；

【导师】 冷永祥；

【作者基本信息】 西南交通大学 ， 材料学， 2008， 硕士

【摘要】 生物材料仅在表面的几个原子层的范围内与生物体发生作用,材料表面的成分与结构、表面形貌、亲疏水性、荷电性、表面能等物理化学状态决定着材料的抗凝血性能。因此寻找一种无机生物材料并对其进行生物化表面改性,是有效改善和提高与血液直接接触的一类生物材料的抗凝血性能的重要途径之一。钽系材料生物无毒性,钽及其氧化物薄膜在生物医学领域已经有了一定的研究和应用,如人造骨、血管支架等。通过调整氧化钽的制备工艺,薄膜具有较宽的表面性质调节范围,在此基础上对其进行生物化表面改性,用于研究材料学因素与材料表面抗凝血性能的关系。本论文采用脉冲非平衡磁控溅射沉积技术制备了不同结构、成分、物理性质和机械性能的氧化钽薄膜,重点研究了反应气体（O₂）与工作气体（Ar）的流量比（O₂:Ar）的变化对薄膜结构和性能的影响。为了在表面获得羟基官能团,对氧化钽薄膜进行高频低压等离子体氢化处理,并采用紫外辐照的方法在薄膜表面产生更多的羟基官能团,最后通过硅烷偶联固定白蛋白（BSA）的方法,使薄膜具有良好的抗凝血性能的材料表面。使用X射线衍射仪（XRD）、X射线光电子能谱仪（XPS）、傅立叶变换红外光谱仪（FTIR）、接触角测试仪、扫描电子显微镜（SEM）等方法对表面改性前后的氧化钽薄膜进行分析和表征,通过体外血小板粘附实验和动物体内实验对改性前后的氧化钽薄膜材料进行抗凝血性能及生物相容性评价。研究结果表明:脉冲非平衡磁控溅射技术沉积的氧化钽薄膜为非晶态,经高真空800℃、60min退火后,转变为相应晶态的氧化钽薄膜,薄膜表面与水的接触角介于82-90°之间,具有一定的疏水性。综合考虑薄膜的表面状态、物理及机械性能,优化出O₂:Ar流量比为0.2的氧化钽薄膜进行表面生物分子固定。等离子体氢化处理导致氧化钽薄膜表面粗糙度增大、疏水性增加。FTIR及薄膜表面与水的接触角结果分析表明,等离子体氢化后用紫外辐照处理的薄膜表面具有一定数量的羟基（-OH）,并显著提高了薄膜表面的亲水性。XPS结果表明,硅烷偶联接枝白蛋白处理后的薄膜表面固定了一定量的白蛋白。体外血小板粘附实验结果表明:高频低压等离子体氢化表面改性对改善氧化钽薄膜的抗凝血性能没有积极贡献;紫外辐照2h后,氧化钽薄膜的抗凝血性能有所提高;表面硅烷偶联固定白蛋白以后,氧化钽薄膜的血液相容性具有一定程度的改善。初步动物体内实验结果表明:在钛金属基体上沉积氧化钽薄膜,并通过硅烷偶联固定白蛋白后,样品表现出优良的生物相容性;高频低压等离子体氢化处理对氧化钽薄膜表面生物相容性的提高没有积极贡献;沉积在金属钛表面未经表面改性的氧化钽薄膜具有良好的生物相容性;（Ta-O）、（Ta-O+氢化）及（Ta-O+氢化+APTES+BSA）工艺的氧化钽薄膜均没有产生血栓,表明其与血管内壁具有良好的组织和生物相容性。更多还原

【Abstract】 Interaction between biomaterials and organism merely occurred in the range of several atomic layers on surface,and anticoagulation property of the biomaterials is affected by their surface properties,such as composition, microstructure,morphology,surface wettability,surface conductivity and surface energy,etc.So it is one of efficacious ways to improve the anticoagulation property of blood-contacting biomaterials by researching a kind of inorganic biomaterials and investigating its biological surface modification.Tantalum-related materials are biologically nontoxic.They were already been investigated and applied into biomedical field,such as vascular stents and artificial bones.In order to research the relationship between material characteristic and anticoagulation property,tantalum oxide films with various surface properties were synthesized by different processing parameters,then surface modification of the films were studied to optimize the biological properties.Tantalum oxide films with different microstructure,composition, physical and mechanical properties prepared by reactive pulse unbalanced magnetron sputtering system were investigated in this study.The effect of gas flow ratio between reactive gas（O₂）and working gas（Ar）on microstructure and properties of tantalum oxide films was mainly studied.For obtaining good antithrombogenic surface,as-deposited tantalum oxide films were treated by plasma hydrogenation,ultraviolet irradiation,silane coupling immobilization and bovine serum albumin immobilization in turn.Pre-and-post modified tantalum oxide films were analyzed and characterized by X-ray diffraction （XRD）,X-ray photoelectron spectroscopy（XPS）,Fourier transform infrared spectrometer（FTIR）,contact angle tester and scanning electron microscopy （SEM）,etc.,respectively.Then vitro platelet adhesion experiments and vivo experiments in animal body were performed to evaluate anticoagulation properties and biocompatibilities of the films.The results showed that tantalum oxide films synthesized by reactive pulse unbalanced magnetron sputtering were amorphous,and transferred to relevant crystal tantalum oxide films via high vacuum annealing at 800℃for 60 minutes.Contact angle of the films were between 80°and 90°which performed a certain hydrophobic property.Tantalum oxide film with O₂:Ar ratio of 0.2 was optimized by comprehensive analysis to immobilize bovine serum albumin.The surface roughness and hydrophobic property of tantalum oxide films were increased by plasma hydrogenation modification.The results of contact angle test and FTIR showed that a certain amount hydroxyl group was observed on the surface of tantalum oxide films after successive plasma hydrogenation and ultraviolet irradiation,and the hydrophilicity on the surface of films was increasing.The result of XPS showed that a certain amount BSA was immobilized onto the surface of tantalum films by APTES.Vitro platelet adhesion experiments indicated that plasma hydrogenation modification did not have positive contribution for improving anticoagulation property of tantalum oxide films.The anticoagulation property of the films was somewhat increased via ultraviolet irradiation for 2 hours and immobilization of BSA by APTES,respectively.The result of preliminary vivo experiments in animal body showed that immobilization of BSA by APTES onto surface of tantalum oxide films synthesized on titanium substrate performed excellent biocompatibility.There was no positive contribution for improving biocompatibility of tantalum oxide films by plasma hydrogenation surface modification.As-deposited tantalum oxide films had good biocompatibility.There was no thrombus on the surface of the films of as-deposited Ta-O films,hydrogenated Ta-O films and BSA immobilized Ta-O films with APTES,which indicated all three kinds of samples had good histocompatibility and biocompatibility with blood vessel inter wall.更多还原