【作者】 张巍；

【导师】 张伯勋； 唐佩福；

【作者基本信息】 中国人民解放军军医进修学院 ， 骨外科， 2009， 博士

【摘要】 骨科内植物在推动骨科发展的同时,也增加了内植物感染的风险。内置物感染是骨科手术后灾难性的并发症,不但给国家和个人造成巨大的经济损失,也对骨科医生提出了巨大挑战。由于内置物感染发生在生物材料与周围组织的界面,而且细菌贴附是感染的始动因素,因此在内置物表面进行抗菌或抑菌修饰成为新的治疗和预防策略。从理论上讲,内置物表面修饰后,局部形成抗菌或抑菌的微环境,可以减少细菌的贴附,提高自身免疫力和抗菌素杀灭细菌的能力。目的:为了降低内植物感染的发生,首先解决细菌在内植物表面种植、贴附这一始动环节。通过分析不同亲疏水表面对细菌贴附影响的作用机理,提出了降低内植物表面亲水程度,形成超疏水表面的设计方案,并验证其抑菌效果。同时,在钛金属表面构建载体层,负载有效抗菌素,观察其抗菌效果。材料和方法:1.通过电化学阳极氧化法在钛金属表面构建TiO₂纳米管阵列薄膜2通过X射线能谱（EDS）、X射线衍射（XRD）、扫描电镜（SEM）和接触角（CA）仪分析TiO₂纳米管阵列薄膜的表面构成、晶体结构、表面形貌以及表面浸润性3.通过自组装的方法,在TiO₂纳米管阵列薄膜的基础上修饰低表面能物质,构建了钛金属超疏水表面4.通过接触角分析自组装后钛金属表面的超疏水性5.通过体外抑菌试验,比较了不同表面对细菌贴附的影响,观察超疏水表面的抑菌效果6.通过药物的吸附和释放实验,观察TiO₂纳米管阵列薄膜的吸附性能7.体内和体外抗菌试验,观察载药TiO₂纳米管阵列薄膜的抗菌效能结果:表面形貌:在含氟溶液中,通过控制反应电压、反应时间等参数,可以在含钛金属的表面制备出形态规则,均匀一致管状结构,形成丛林状纳米管阵列。结构表征:纳米管阵列仅由钛元素和氧元素构成,不含任何其它元素。通过热处理可以改变TiO₂纳米管的晶型,加热到450℃后,由无定型转变成锐钛矿型。钛金属表面氧化成纳米管阵列后,其表面亲水性增加,接触角由原来的80.4°±1.5°下降到48.6°±1.0°,和20.2°±2.7°。超疏水表面抑菌效果:在TiO₂纳米管阵列表面修饰低表面能物质PETS,其接触角可以达到156°±1.0°。体外抑菌试验证明:相对于亲水和普通疏水表面,其抑菌程度可以降低50%-90%,能够有效降低细菌贴附。TiO₂纳米管载药和释放:TiO₂纳米管有强大的吸附能力,可以将万古霉素和妥布霉素吸附到管内。但是从释放角度考察,抗菌素释放较少,释放的时间不规律,需要进一步探索研究。载药TiO₂纳米管抗菌实验:体外实验证明,载药TiO₂纳米管可以减少细菌贴附,相对于为载药组减少贴附程度达到50%。动物实验证明,在适当浓度,载药TiO₂纳米管可以改善骨感染和骨髓炎临床症状。核素骨扫描:股骨下端感兴趣区,载药侧放射性计数明显低于对照侧。Micro CT:明确观察到对照侧,皮质骨破坏和骨膜反应,而载药侧不明显。病理结果与Micro CT结果一致,对照侧骨髓感染程度、皮质骨破坏和骨膜反应程度明显高于载药侧。结论:1.电化学阳极氧化法在钛金属表面构建了TiO₂纳米管阵列薄膜。2.在TiO₂纳米管阵列表面,可以形成超疏水表面,并且能大大降低细菌的贴附和种植。3.TiO₂纳米管吸附能力强大,可能成为新型药物载体,吸附有效抗菌素治疗或者预防内植物感染更多还原

【Abstract】 Though implants promotes the development of orthopeadics,it increases the risk of infection.The complication of infection causing by implants is a disaster which leads to much money loss and challenges the decision of orthopeadist on treatment.Superficial bacteriostatic or antibacterial modification of implants becomes a new treatment or prevention for that the infection occurs at the interface between the implants and surrounding tissues and begins from the adhesion of bacterial. Theoretically,The bacteriostatic or antibacterial microenvironment forming after the surface modification reduces the adhesion of bacterial,improving autoimmunity and the antibiotic ability in bacterial-killing.Objective:In order to reduce the infection probability of implants,the problem of bacterial planting and adhesion on the surface,the first step of infection,is the first one to solve.Analyzing the action mechanism of bacterial adhesion to different hydrophilic and hydrophobic surfaces of implants,a design proposal is raised here to decrease the surface hydrophilicity and turn it into super-hydrophobicity,and the result of bacteriostasis was verified also. Meanwhile,a carrier-section carrying effect antibiotic was made on the titanium surface and the result was observed.Material and methods:1.Using the electrochemistry anodic oxidation method to make a membrane of TiO₂ nanotube arrays at the titanium surface.2.Using x-ray electromagnetic spectrum（EDS）、x-ray diffraction（XRD）、scanning electron microscope（SEM）and contact angle（CA）analysator to analyze the surface composition、crystal structure、surface shape and surface invasion of the membrane of TiO₂ nanotube arrays. 3.Using a self-assembly method,at the basis of the membrane of TiO₂ nanotube arrays,to make a super-hydrophobic surface by modifying the surface with a hypo-energy materials.4.Analying the super-hydrophobicity of titanium surface after self-assembly through a CA analysator5.Comparing the effects of different surfaces on bacterial adhesion in vitro,6.Observing the adsorbability of the membrane of TiO₂ nanotube array through the experiment of medicamentous adsorbing and delivering.7.Observing the antibiosis efficacy of the membrane of TiO₂ nanotube array with medicine through vivo and vitro antibiosis experiments.Results:Surface shape:by controlling the parameters of reaction voltage and reaction time,a regular and uniformity tubiform can be made on the Ti-surface and forming a brush of nanotube array in a solution with fluorine.The character of the surface structure:Nanotube arrays include no elements but Ti and oxygen.Its crystal form can be changed with heat-treatment.When the temperature was reached on 450℃,it can be turned from amorphous type into anatase type.After oxidization of the nanotube array on the Ti-surface,its hydrophilicity increases,and the CA decreases from 80.4°±1.5°to 48.6°±1.0°and 20.2°±2.7°.The bacteriostasis result of hyper-hydrophobic surface:When modificationing the TiO₂ nanotube array with hypo-energy surface material PETS, the CA can be 156°±1.0°.As certificated by vitro experiment of bacteriostasis, compare to hydrophilic and common hydrophobic surfaces,the bacteriostasis function of hyper-hydrophobic surface may degrade by 50%-90%which can reduce the bacterial adhesion effectively.Medicine loading and delivering of TiO₂ nanotube:the adsorbability of TiO₂ nanotube is great,and the Vancomycin and Tobramycin can be absorbed into tubes.But to the aspect of antibiotic dilivery,it is less and unregular and needs further exploratory and investigation.The antibiosis experiment of ZiO₂ nanotube with medicine:As verified by vitro experiment,TiO₂ nanotube with medicine cannot decrease bacterial adhesion, but can kill 50%-90%attached bacterial.In animal experiment,TiO₂ nanotube with vancomycin medicine can improve the clinic symptoms of bone Infection and osteomyelitis.As demonstrated on bone scan,compared to the control side, the ROI values on the inferior femur of trial side were much less.And on micro CT,contrast to the trial side,cortical bone destroy and periosteal reaction can be seen on control side obviously.The result of pathology is the same as micro CT, that is that the degree of bone marrow infection、cortical bone destroy and periosteal reaction on the trial side is higher than the control side.Conclusion:1.a membrane of TiO₂ nanotube array was made at the titanium surface with galvanochemistry anodic oxidation methods.2.On the surface of the membrane of TiO₂ nanotube array, super-hydrophobic surface was formed,decreasing the ability of bacterial adhesion and planting obviously.3.The adsorbability of TiO₂ nanotube is great and it can become a new medicine-carrier adsorbing effective antibiotic to treat or prevent the infection causing by implants.更多还原