紫外光处理对纳米化钛表面理化性能及生物学活动影响的机制探究

发布时间：2018-08-02 18:16

【摘要】：[背景]:牙种植技术因其理想的修复失牙效果在临床上得到广泛的应用。但因人工种植牙植入到骨内后需有3～6个月的骨结合进程,在此期间一方面导致不能及时恢复患者的咀嚼及语言等功能,另一方面骨结合所需时间越长,期间在外力作用下出现失败的风险越高。目前希望通过钛表面处理技术加速种植体植入后的骨结合过程,实现即刻种植和早期负重已成为牙种植学研究的热点之一。为了克服传统微米级种植体在即刻种植体应用中的局限性,纳米级修饰钛种植体表面改性不断被提出,纳米级修饰能够更好的模拟体内骨组织环境,有效促进种植体-骨结合的发生、发展。另外,“种植体老化”也是临床上常面临的难题之一。已有研究证实传统表面修饰种植体可随保存时间延长出现表面能的改变,影响骨结合过程。本课题组前期的研究已证实紫外光催化(Ultraviolet,UV)可有效改善钛种植体的表面能,提高骨结合效能。从理论上分析,采用体表面积更高的纳米级修饰替代传统微米级修饰种植体,紫外光催化的效能应随材料比表面积增加而提高,但实际上UV处理纳米级修饰钛表面对其生物学及表面理化性能影响,特别是表面元素改变及电荷状态的影响仍需要进一步探究。[目的]:研究紫外光处理对纳米级修饰钛表面理化性能及生物学活性的影响。[方法]:利用阳极氧化技术,在纯钛表面制作纳米管形貌(AO组)并对其进行紫外光催化(AO+UV组)。采用扫描电镜(SEM)、表面粗糙度测试仪、XPS能谱仪、接触角测试仪、固体Zeta电位仪对材料表面的理化特性进行分析。采用体外蛋白吸附实验和体外细胞学实验来检测两组材料的早期生物学活性。[结果]:利用阳极氧化技术在纯钛表面稳定的制备出70-100nm管径的钛纳米管形貌。SEM及表面粗糙度结果显示UV催化前后的钛纳米管表面在形态学表征和表面粗糙度上均未表现出明显差异。UV处理提高了钛纳米管表面的亲水性,接触角由51.5°变为6.2°。采用XPS对钛纳米管表面UV催化前后元素组成进行分析发现,UV催化降低了纳米管表面无机物及有机物污染,并暴露出更多Ti3+、Ti4+位点。然而更值得注意的是O元素峰值的变化。经紫外光催化后,钛纳米管表面酸性羟基峰值明显减小而碱性羟基增多。通过两组实时电位测定发现,UV处理后的钛纳米管表面等电点降低,在体液条件下所携带的负电荷明显减少。体外生物学实验结果显示,UV催化大大提高了蛋白在材料表面的吸附能力,AO+UV组钛表面孵育3h吸附量甚至高于AO组24h吸附量。UV处理明显提高了成骨细胞在钛纳米管表面的早期黏附活动,提高了成骨细胞在其表面的黏附率,影响细胞的黏附形态,促进细胞骨架的改建和黏着斑的形成。[结论]:UV处理促进了钛纳米管的早期生物学活动,这与其表面酸碱性羟基改变导致的材料表面电荷变化有关。
[Abstract]:Background: dental implant is widely used in clinic because of its ideal restoration effect. However, it takes 3 to 6 months for the artificial implant teeth to be implanted into the bone. During this period, the mastication and language functions of the patients can not be restored in time, and the longer the time of bone bonding is, The higher the risk of failure during external force. At present, it is hoped that the process of bone bonding after implant implantation can be accelerated by titanium surface treatment, and the realization of immediate implantation and early loading has become one of the hotspots in dental implant research. In order to overcome the limitations of traditional micron implants in the application of immediate implants, surface modification of titanium implant with nano-scale modification has been proposed, and nano-scale modification can better simulate the bone tissue environment in vivo. To promote the development of implant-bone bonding. In addition, implant aging is one of the most common clinical problems. It has been proved that the surface energy of the traditional surface modified implants can change with the prolongation of the preservation time, which affects the bone binding process. It has been proved that Ultraviolet UV can effectively improve the surface energy of titanium implants and improve the bone binding efficiency. Theoretically, the effect of UV photocatalysis should be improved with the increase of the specific surface area of the material by using nano-scale modification with higher surface area instead of the traditional micrometer modified implant. However, the effects of UV treatment on the biological and physical and chemical properties of titanium surface, especially the changes of surface elements and the charge state, need to be further explored. Objective: to study the effects of UV light treatment on the surface physicochemical properties and biological activity of nano-modified titanium. [methods] Nanotube morphology (AO group) was prepared on pure titanium surface by anodic oxidation technique. The nanotubes were prepared by UV photocatalytic (AO UV group. The physical and chemical properties of the material surface were analyzed by scanning electron microscope (SEM) (SEM), surface roughness tester, contact angle tester and solid Zeta potentiometer. In vitro protein adsorption test and in vitro cytological test were used to detect the early biological activity of the two groups. [results]: the morphology and surface roughness of titanium nanotubes with 70-100nm diameter were prepared stably on pure titanium surface by anodic oxidation technique. The results showed that the surface morphology and surface roughness of titanium nanotubes before and after UV catalysis were the same. The surface hydrophilicity of titanium nanotubes was improved by UV treatment without obvious difference. The contact angle changed from 51.5 掳to 6.2 掳. The elemental composition of titanium nanotubes before and after UV catalysis was analyzed by XPS. It was found that UV catalysis reduced inorganic and organic contamination on the surface of titanium nanotubes and exposed more Ti3 Ti4 sites. More notable, however, is the change in the peak value of the O element. After UV photocatalysis, the peak value of acidic hydroxyl groups on the surface of titanium nanotubes was decreased and the basic hydroxyl groups increased. After UV treatment, the surface isoelectric point of titanium nanotubes was decreased, and the negative charge carried in body fluid was obviously decreased by measuring the real time potential of the two groups. The results of biological experiments in vitro showed that UV catalysis greatly enhanced the adsorption capacity of protein on the surface of titanium. The amount of adsorption on titanium surface of AO UV group was even higher than that of AO group after incubation for 3 h. UV treatment significantly increased osteoblast adsorption on titanium nanotubes. Early adhesion to the surface, The adhesion rate of osteoblasts on the surface of osteoblasts was increased, the adhesion morphology of the cells was affected, and the remodeling of cytoskeleton and the formation of adhesion plaque were promoted. [conclusion] UV treatment promoted the early biological activities of titanium nanotubes, which was related to the change of surface charge caused by the change of acid, basic and hydroxyl groups on the surface of titanium nanotubes.
【学位授予单位】：南方医科大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R783.6

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