【作者】 成夙；

【导师】 周玉；

【作者基本信息】 哈尔滨工业大学 ， 材料学， 2012， 博士

【摘要】 本文采用微弧氧化的方法在实体钛及微珠烧结的多孔钛表面制备了TiO₂基含硅钙元素的微弧氧化涂层。通过后续热处理和水热处理的方法对实体钛表面微弧氧化涂层进行表面改性。采用X射线衍射（XRD）、拉曼光谱（Raman）、扫描电子显微镜（SEM）、原子力显微镜（AFM）、X-射线光电子谱（XPS）、傅立叶变化红外光谱（FT-IR）、透射电子显微镜（TEM）、力学万能实验机和纳米压痕仪等分析手段研究了实体钛表面微弧氧化涂层改性前后和多孔钛表面微弧氧化涂层的组织结构、力学性能、物化性能及涂层在模拟体液中诱导磷灰石的能力。采用酶标仪、激光共聚焦显微镜（CLMS）、紫外分光光度计等分析手段，研究了涂层表面细胞增殖、黏附、细胞骨架、细胞活性等细胞学行为和血液相容性。通过种植体兔胫骨体内植入的实验方法、采用X射线影像、Micro-CT、生物力学测试、组织学切片等分析手段研究了种植体与兔胫骨组织的结合能力和体内相容性。此外，为解决植入体导致的炎症问题，本文研究了在涂层表面上载抗生素药物及释放机制。本文采用了100、200、400、600μm直径的钛珠真空烧结制备了多孔钛。采用EDTA-2Na⁺Ca(（CH₃COO）₂.H₂O+Na₂SiO₃.9H₂O+NaOH的电解液，在实体钛和多孔钛表面制备了TiO₂基含硅钙微弧氧化涂层（SC）。SC涂层中主要物相为锐钛矿，涂层和基体之间界面结合良好。SC涂层中主要含有Ca、Si、Na、Ti和O元素。随着微弧氧化电压升高，SC涂层表面Ca、Si和Na含量增加，Ti含量降低。各种元素在涂层内部存在梯度分布。SC涂层中Ti、O、Ca、Si分别对应Ti⁴⁺和Ti²⁺、O^2-、Ca²⁺、Si⁴⁺化学态。电压对Ca和Si元素的化学态没有明显的影响。随着制备电压增高，SC涂层表面硬度、弹性模量、抗腐蚀性提高,润湿性和表面粗糙度增加。随着钛珠直径的增加，多孔钛孔隙率与力学性能逐渐降低。多孔钛SC涂层厚度随钛珠直径增加而升高。SC涂层经过700℃和800℃热处理后表面形成金红石和榍石，表面变得粗糙，涂层厚度增加，抗腐蚀性能和力学性能提高。SC涂层热处理后除了Ti²⁺转化为Ti⁴⁺以外，其它各个元素的化学态不变。水热处理SC涂层表面形成竹叶状、条状、线状TiO₂。在水热反应过程中，Si、Ca离子发生溶解。此外，SC涂层水热处理过程中，涂层中的TiO₂会受到OH-离子的攻击，形成HTiO₃^-离子，引起Ca²⁺和Na⁺离子在涂层表面沉积，从而形成钛酸钙和钛酸钠水合物。在SBF浸泡过程中，SC涂层中的Na⁺离子能够和SBF中的H₃O⁺离子发生离子交换形成Si-OH，增强了磷灰石的形核。而且磷灰石能够生长嵌入SC涂层的微孔中。此外，电压增加使得SC涂层中Si、Ca含量增加，从而提高了磷灰石诱导能力。多孔钛SC涂层磷灰石诱导能力优于实体钛SC涂层，主要由于多孔结构和多孔钛SC涂层中引入的Si、Ca元素的含量高。由于榍石相的增多，热处理SC涂层随热处理温度升高诱导磷灰石能力增强。SC涂层经过水热处理以后形成HA和钛酸盐水合物，磷灰石诱导能力明显增强。在SBF浸泡过程中，钛酸盐水合物中的Ca²⁺和Na⁺离子与SBF中的H₃O⁺离子发生交换形成Ti-OH，提高了磷灰石形成能力。各种诱导的磷灰石都含有HPO4^2-和CO3^2-等功能团。SC涂层及其改性涂层表面上载的头孢唑林钠/壳聚糖复合药物薄膜具有药物缓释性能。药物薄膜能够沉积到微弧氧化的微孔中，涂覆次数增加、壳聚糖的引入能增强头孢唑林钠的缓释能力。800oC热处理SC涂层表面药物缓释能力略好于其它涂层。多孔钛SC涂层表面药物缓释能力好于实体钛SC涂层，因为多孔钛具有更大的承载药物空间。壳聚糖和头孢唑林钠之间主要通过库伦作用、范德华力作用、氢键作用等形式进行结合。药物薄膜和SC及热处理SC涂层之间也会出现各种物理化学吸附反应，涉及到涂层的Si-OH、Ti-O结构和药物的-C=O、OH、-NH2基团发生作用。随着微弧氧化电压增高，SC涂层表面细胞增殖能力增强，涂层表面细胞活性与纯钛无差别，细胞骨架结构优于纯钛表面。多孔钛SC涂层表面细胞黏附能力早期弱于纯钛表面，但是后期黏附能力强于钛表面，且细胞黏附形态与钛珠直径有关。多孔钛SC涂层利于早期的细胞增殖，细胞培养7天后与未氧化多孔钛增殖能力无显著差别。不同直径钛珠烧结多孔钛SC涂层表面细胞活性差别不显著，多孔钛结构利于优化表面细胞肌动蛋白骨架。随着热处理温度提高，SC涂层表面的细胞黏附，增殖、细胞活性等均提高，细胞形态与骨架结构优良。水热处理SC涂层表面利于细胞黏附和增殖，细胞黏附形态完整。不同水热处理条件制备的SC涂层表面细胞黏附率、增殖率和细胞活性无显著差别。本实验各种涂层均无溶血能力，血液相容性良好。不同电压制备的SC涂层种植体、热处理SC涂层种植体植入兔胫骨内，体内相容性优良，在植入期间无排斥感染现象出现。种植体周围骨组织吸收良好，沿种植体有骨组织生长。自兔胫骨内取出的种植体可观察到沉积的骨组织和成骨细胞，骨组织与种植体的结合强度随微弧氧化电压和热处理温度增加而加强。多孔钛SC涂层种植体植入兔胫骨内，表现出的生物性能与实体钛SC种植体类似，但是与骨组织的结合强度高于实体钛SC涂层，因为多孔钛SC涂层的孔隙中有骨组织的长入。组织学观察植入兔体内三个月各种种植体均与骨组织良好结合。综上，本文中实体钛SC涂层、热处理和水热处理实体钛SC涂层及多孔钛SC涂层展现出了优良的磷灰石诱导能力、细胞相容性、血液相容性和体内生物活性，同时涂层表面涂覆头孢唑啉钠/壳聚糖药物膜具有明显的缓释作用。更多还原

【Abstract】 Microarc oxidation （MAO） was used to produce TiO^2-based coatingscontaining Si and Ca on the surfaces of the entitative Ti and porous Ti prepared bysintering Ti beads. And then, the MAO coatings were modified by heat-treatmentand hydrothermal-treatment to enhance their bioactivity. The microstructures,mechanical properties, physical and chemical properties and apatite-formationability of the MAO coatings before and after modification were investigated by theX-ray diffraction（XRD）, raman spectroscopy（Raman）, scanning electronicmicroscope（SEM）, atomic force microscope（AFM）, X-ray photoelectronicspectroscopy（XPS）,fourier transform-Infrared spectra （FT-IR）,transmission electronmicroscope（TEM）, mechanics universal testing machines and nanoindentation. Theblood compatibility and cell biological behaviors such as cell proliferation, cellattachment, cytoskeleton and cellular activities of the MAO coatings without andwith modifications were investigated by microplate reader for ELISA, Laserscanning confocal microscope（CLMS） and ultraviolet-visible pectrophotometer. Thein vivo compatibility and bonding strength of the implants covered MAO coatingswithout and with subsequent modifications between new bones were investigatedafter implanting in rabbit tibia for different time by X-ray Diagnostic imaging,Micro-CT, Biomechanics, histologic cross-sectional anatomy. In addition, toovercome the inflammation resulted from implants, drug coating technique was usedto deposit antibacterial drugs on implants.In this paper, porous titanium was fabricated by sintering titanium beads withdifferent diameters of100,200,400and600μm. TiO^2-based coatings containing Siand Ca （SC） were prepared on entitative Ti and porous tianium in the electrolytecontaining EDTA-2Na, Ca(（CH₃COO）₂.H₂O, Na₂SiO₃.9H₂O and NaOH. The mainphase compositions of SC coatings are anatase and the main elemental compositionsare Ca, Si, Na, Ti and O. And the interface bonding strength between SC coatingsand Ti is good. With increasing the applied voltage, the concentrations of Ca, Si andNa increased and that of Ti decreased. A graded distribution in the elementalconcentration along the coating depth was observed. In the current results, thechemical states of Ti, O, Ca and Si were Ti⁴⁺and Ti²⁺, O^2-, Ca²⁺, Si⁴⁺. At the sametime, the applied voltage does not affect the chemical states of Ca and Si. In addition,the hardness, elastic modulus and corrosion resistance of SC coatings wereenhanced and the wetting ability and surface roughness of SC coatings improved byincrease the applied voltage. With increasing the titanium bead diameter, theporosity and mechanical properties decreased. In addition, the thickness of the SC coatings on the porous titanium increased.After heat treatment of the SC coating at700℃and800℃, rutile and sphenewere formed. With increasing heat treatment temperature, the surfaces of SCcoatings became rougher and the coating thickness, corrosion resistance andmechanical properties were improved. After heat treatment of SC coatings, except ofthe change in the chemical states of Ti²⁺to Ti⁴⁺, the chemical states of Ca, Si and Oelements did not change. On the surface of hydrothermal heated SC coatings,bamboo-, band-and line-like TiO₂were observed. During the hydrothermaltreatment process, Si and Ca elements were released into the NaOH aqueoussolution. In addition, TiO₂of SC coatings could be attacked by OH-ions in theNaOH aqueous solution, forming HTiO₃^-ions, which could result in the depositionof Ca²⁺and Na⁺ions on the modified surface to form calcium titanate and sodiumtitanate hydrates.During SBF immersion, the ionic exchange of Na⁺ions of SC coating with H₃O⁺ions in SBF can result in the formation of Si-OH groups, greatly promoting theapatite formation on the SC coatings. At the same time, the apatite can deposit in themicropores of SC coatings. In addition, increasing the applied voltage couldimprove the apatite forming ability of SC coatings due to high Ca and Siconcentrations in the SC coatings. The apatite forming ability of the porous titaniumis higher than that of entitative Ti due to its porous structure and higherconcentrations of Si and Ca. with increasing the heat treatment temperature, theapatite forming ability of SC coatings increased due to the formation of sphene. Thehydrothermal treated SC coatings show high apatite formation ability resulting fromthe formation of HA and titanates. During the SBF immersion process, the ionicexchanges of Ca²⁺and Na⁺ions of titanates on the hydrothermal treated SC coatingswith H₃O⁺ions in the SBF cause the formation of Ti-OH groups, which greatlyimprove the apatite formation ability. In addition, the induced apatites by all kindsof coatings contain HPO4^2-and CO3^2-groups.The cefazolin sodium/chitosan drug films on the SC coating show drugslow-release ability. The drug films could deposit into the micropores of SCcoatings. The increase of deposition times and the addition of chitosam can improvethe slow-release ability of drug film. And the slow-release ability of drug films onthe heat-treated SC coating at800oC is higher than that of other coatings. Thereactions between chitosam and cefazolin could involve coulombic interactions, vander Waals force, and H-bonding etc. In addition, interface reactions between drugfilms and SC and heat-treated SC coatings could occur such as physical andchemical absorption involving various groups such as Si-OH, Ti-O of substrates and-C=O,-OH and-NH2groups of drug films.The cell proliferation on the surface of SC coatings increased with increasing the applied voltage. The effect of SC coatings on the cellular activity is not obviouscompared to pure titanium. The cell attachment ability on the porous titanium withSC coatings was lower than that on pure titanium at the early cell culture. However,it enhanced at latter cell culture. Moreover, the morphology of the attached cells isrelative to the diameter of titanium beads. The porous titanium with SC coatings isbenefit to the cell proliferation at early cell culture after1and3days, however, noobvious difference in the cell proliferation was observed between porous titaniumwithout and with SC coatings after cell culture for7days. The effect of the titaniumbeads diameter on the cellular activity is not obvious. However, the porous structureof porous titanium could optimize the cell actin skeleton. With increasing the heattreatment temperature, the cell attachment, cell proliferation and cellular activitywere enhanced, at the same time, the cytoskeleton and cell morphology are good.Hydrothermal treatment could improve the cell proliferation and attachment on theSC coatings. In addition, the attaching morphology on the hydrothermal treated SCcoatings is integrity. The hydrothermal treatment procedure has not evident effect onthe cell attachment ratio, cell proliferation and cell activity. No All coatings showgood blood compatibility.The in vivo biocompatibility of the SC coatings before and after heat treatmentis very good, and no rejection and infection were found after implantation. Moreover,the bone tissue absorption is also good, and new bone could grow on the surface ofthe implants. The bone tissue and osteoblast could be observed on the surfaces of theimplants after being taken out from the rabbit tibia. The bonding strength betweennew bone and implants increased with increasing the applied voltage and heattreatment. The porous titanium with SC coatings shows similar in vivobiocompatibility compared to entitative Ti with SC coatings. However, the bondingstrength between implants and new bones is higher than that of entitative Ti, sincethe new bone can grow in the pores of the porous titanium. Good interfaces of newbones and various implants were observed after implanting for3months in rabbit.Above all, the entitative Ti with SC coatings before and after heat treatment orhydrothermal treatment, as well as the porous titanium with SC coatings, showsgood apatite forming ability, cell compatibility, blood compatibility and in vivobiocompatibility. In addition, The cefazolin sodium/chitosan drug films on the SCcoating show drug slow-release ability.更多还原