【作者】 王锦标；

【导师】 黄楠； 杨苹；

【作者基本信息】 西南交通大学 ， 材料学， 2011， 博士

【摘要】 抗凝血性是与血液接触的生物器械和人工器官中存在的主要问题,提高抗凝血性对于这类生物材料的发展和应用至关重要。无机材料表面的血液相容性与材料的结构性能,特别是表面特性有密切关联,因此,考察材料表面结构性能与抗凝血性之间的关系,了解材料表面与血液之间的界面作用行为,揭示抗凝血表面改性机制,探索材料处理工艺和方法,对于调控和制备具有优良血液相容性医疗器械和生物材料的发展具有重要的理论指导和实际应用意义。本论文利用非平衡磁控溅射技术合成了一定结构和性能的氧化钛薄膜；利用离子注入以及真空退火对氧化钛薄膜进行了后续改性处理。利用扫描电镜(SEM)和原子力显微镜(AFM)对薄膜表面形貌和粗糙度进行了分析；综合采用X射线衍射(XRD)、X射线光电子能谱(XPS)、价带谱(VXPS)和傅里叶红外光谱(FTIR)对薄膜的结构和成分进行了表征；利用四探针电阻仪和接触角测试仪对薄膜的导电性和表面能进行了测量；采用体外评价方法对薄膜的血液相容性进行了评价。通过对离子注入和真空退火对氧化钛薄膜结构、性能以及抗凝血性的考察,建立了氧化钛薄膜结构与性能之间一定的联系,对氧化钛薄膜的抗凝血机理进行了一定的解释,主要结论如下：1.离子注入和真空退火对氧化钛结构和性能的影响(1)真空退火后,单晶Ti02以及氧化钛薄膜由近似无色变为深蓝色,薄膜导电性提高,薄膜表面存在Ti3+,表面羟基含量增加,亲水性提高,表面能极性分量增加。热致氧空位和低价钛的产生导致：①氧化钛薄膜的能带结构发生变化,方块电阻降低；②对光波的特异性吸收使得氧化钛呈深蓝色；③H2O在氧空位分解生成-OH,表面羟基含量增加,亲水性提高,表面能极性分量增加。(2)真空退火后,氧化钛薄膜优异的亲水性在一定时间的存放后丧失,表面羟基含量减少。环境物质在高活性氧化钛薄膜表面的复杂解离、吸附反应导致表面氧空位被愈合,羟基被替代或掩盖,亲水性降低。(3)离子注入造成氧化钛薄膜晶体结构损伤,薄膜导电性提高。真空退火对晶格损伤有修复作用,同时导致薄膜方块电阻进一步降低。离子改性薄膜的亲水性和表面吸附态同时受到离子注入、退火和氧化钛薄膜的共同影响而表现出多样性变化。2.氧化钛薄膜结构性能与血液相容性的联系(1)真空退火导致的羟基化表面使得氧化钛薄膜的抗凝血性显著提高。①表面羟基含量增加,使得薄膜表面亲水性以及表面能极性分量提高,富含羟基的、亲水的、表面能极性分量与色散分量比值高的氧化钛薄膜表面有利于减少纤维蛋白原的吸附量、维持其正常构象、减少血小板的激活,从而使得氧化钛薄膜的抗凝血性能提高。②表面氧空位和低价钛在产生羟基化表面的同时还会形成n性半导体特征的能带结构,抑制纤维蛋白原变性,从而提高薄膜的抗凝血性。③当氧化钛薄膜表面的氧空位被逐渐愈合,羟基被其他吸附物替代或掩盖,薄膜的亲水性降低、表面能极性分量与色散分量比值降低,氧化钛薄膜在退火后优异的抗凝血性能逐渐丧失。(2)离子注入改性处理后,当薄膜表面吸附氧比例如果超过50%,将导致表面黏附血小板激活程度的加剧,退火处理如果使吸附氧比例降至50%以下则会降低血小板的激活程度。更多还原

【Abstract】 The antithrombogenicity remains a primary problem for the biomaterials used in blood-contacting medical devices and artificial organ, the improvement of anticoagulation is therefore critical for the development and application of these biomaterials. There is a close relationship between the hemocompatibility of inorganic materials surface and the structure and properties, especially the surface characteristics, of materials. In this light, it is necessary to investigate the causal relationship between materials surface characteristics and antithrombogenicity, understand the interactions occur in the interface between blood and materials, reveal the mechanism of enhancing antithrombogenicity by surface modification, and explore the technics and methods of material processing. The results of above studies are of theoretical significance and practical value in the design of biomaterials and medical device with good hemocompatibility.In this work, titanium oxide films with diverse structures and properties were fabricated by unbalanced magnetron sputtering, and then utilize ion implantation and vacuum annealing to modify the film.The surface topography and roughness of the films were analyzed by Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM). The structure and composition of the film were characterized by X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and its valence band spectroscopy (VXPS), Fourier Transform Infrared Spectroscopy (FTIR). Four-point probe resistance meter and contact angle apparatus were employed to measure the electroconductibility and surface energy respectively. In vitro test is used to evaluate the hemocompatibility of Ti-O film.Through the analysis of the effect of ion implantation and vacuum annealing on structure, property and antithrombogenicity of Ti-O film, to a certain extent, some causal relationships between structure and property have been established. The main conclusions of this dissertation were as follows:1. The effect of ion implantation and vacuum annealing on structure and property of Ti-O film(1) After treated by vacuum annealing, the color of monocrystal TiO2and Ti-O film turn from approximate colorless to mazarine, the conductivity of film improved, on the surface of film exist Ti3+, hydroxy content, hydrophilia and the polar fraction of surface free energy all increased. The generation of thermally induced oxygen vacancy and low-valent titanium lead to three results:①The energy band structure of the film have been changed, and the square resistance reduced.②The specific absorption of light wave cause the Ti-O film shows mazarine.③When H2O contact with oxygen vacancies, the H2O decomposed to form-OH. Consequently, hydroxy content, hydrophilia and the polar fraction of surface free energy all increased.(2) Treated by vacuum annealing, and after a period time, the remarkable hydrophilia of Ti-O film disappear, the hydroxy content on the surface decreased. The complex reactions, which ambience substance take part in and include dissociation and adsorption, take place on the surface of Ti-O film lead to the disappearance of oxygen vacancies, and the hydroxyls were replaced or blanketed, hydrophilia reduced finally.(3) Ion implantation cause the damage of crystal structure, this has further led to an improvement in conductivity of film. Vacuum annealing can repair the damage of crystal lattice, and this result in further reduction of film square resistance. The hydrophilia and surface adsorption states of film modified by ion implantation were mediated by effect of the ion implantation and vacuum annealing collectively and present diversity.2. The relationship between hemocompatibility and the structure and property of Ti-O film(1) Surface hydroxylation caused by vacuum annealing improves the antithrombogenicity of Ti-O film obviously.①With the increase of the surface hydroxy content, hydrophilia and the polar fraction of surface free energy of film surface improved. The Ti-O film with abundant hydroxyl, excellent hydrophilia and high ratio of polar to disperse component of surface free energy could be beneficial to reduce the adsorption of fibrinogen, keep it normal conformation and minimize the platelet adhesion on the surface, so improve the antithrombogenicity of the film.②Oxygen vacancy and low-valent titanium lead to the surface hydroxylation of film and form the energy band structure with n-type semiconductor feature simultaneously, and this structure restrains the degeneration of fibrinogen, thus the antithrombogenicity of the film been improved.③Oxygen Vacancy were be healed, the hydroxylation were be replacement or concealment by other adsorbate, the hydrophilic of the surface decrease, and the ratio of polar component to disperse component of surface free energy decrease, the advantage antithrombogenicity caused by vacuum annealing attenuated gradually.(2) If the percentage of adsorption oxygen more than50%after ion implation, the antithrombogenicity would be decrase; furthermore, the blood compatibility of the film will be improve if the percentage of adsorption oxygen less than50%after vacuum annealing treatment.更多还原