316L不锈钢表面纳米孔阵列、三维石墨烯的制备及其生物相容性研究

发布时间：2018-06-02 00:18

本文选题：316L不锈钢 + 两步阳极氧化　；参考：《武汉科技大学》2016年硕士论文

【摘要】：316L奥氏体医用不锈钢具有良好的机械力学性能、较强的抗腐蚀性能及价格低廉等优点,因此在医用领域存在巨大潜在应用价值。但316L不锈钢较低的生物相容性及其含有铬、镍等生物毒性元素的缺点限制了其应用。本文采用两步阳极氧化法在316L医用不锈钢表面制备出纳米孔阵列氧化层且氧化层内Cr、Ni元素的含量相对不锈钢基体而言有大幅度降低,从而来改善其生物相容性。此外,二维(2D)石墨烯由于片层间的范德华力而容易发生团聚,这使得2D石墨烯的独特性能受到限制;三维(3D)石墨烯不仅能够保持2D石墨烯的特有性能,而且在实际应用中的其他性能还能得到增强,因而受到广泛关注。但3D石墨烯的生物学影响到目前仍不清楚。由于3D石墨烯在生物医用领域存在巨大应用前景,本文以316L医用不锈钢表面纳米孔阵列为模板制备出3D石墨烯且对其体外生物相容性作了系统性评估。1.采用两步阳极氧化法在316L不锈钢表面制备出孔径可控的纳米孔阵列。在第二步阳极氧化过程中,纳米孔孔径受电压的影响且在一定范围内与阳极氧化时间之间存在线性关系。相对于第一步阳极氧化而言,在孔径没有明显扩张的情况下,第二步阳极氧化所生成的纳米孔深度是之前的7倍。经过第二步阳极氧化的不锈钢表面不存在零价的Fe、Cr和Ni且X射线光电子谱(XPS)检测谱中没有出现Cr、Ni的信号峰;2.以聚多巴胺为碳源,在孔径分别为50nm和240nm的不锈钢表面纳米孔阵列上制备出3D石墨烯,用NIH-3T3成纤维细胞对其体外生物安全性做了评估。纳米孔阵列有效改善了316L不锈钢的生物相容性。三维石墨烯则引起了细胞毒性,毒性大小与其三维构型有关;毒性的产生是由于细胞吞噬了三维石墨烯层中的纳米碳球,随之阻碍了细胞内黏附蛋白和肌动蛋白丝的合成,最终导致细胞凋亡。
[Abstract]:316L austenitic medical stainless steel has good mechanical and mechanical properties, strong corrosion resistance and low price, so it has great potential application value in medical field. However, the low biocompatibility of 316L stainless steel and the shortcomings of its biotoxic elements, such as chromium and nickel, limit its application. In this paper, nano-porous array oxidation layer was prepared on the surface of 316L medical stainless steel by two-step anodization method. The content of Cr-Ni in the oxidation layer was decreased significantly compared with the stainless steel matrix, thus improving its biocompatibility. In addition, 2D / 2D) graphene is prone to agglomeration due to van der Waals force, which limits the unique properties of 2D graphene, and 3D / 3D) graphene can not only preserve the unique properties of 2D graphene, And other performance in practical applications can also be enhanced, so it has received wide attention. However, the biological effects of 3 D graphene are still unclear. Because 3D graphene has great application prospect in biomedical field, 3D graphene was prepared by using 316L medical stainless steel surface nano-porous array as template and its biocompatibility in vitro was systematically evaluated. Two-step anodizing method was used to fabricate nano-pore arrays with controllable pore size on 316L stainless steel surface. In the second step of anodic oxidation, the pore size is affected by the voltage and has a linear relationship with the anodic oxidation time in a certain range. Compared with the first step of anodizing, the depth of the nano-pore generated by the second step anodizing is 7 times that of the former without obvious expansion of the pore size. The surface of stainless steel after the second step anodization does not have zero valence FeNCr and Ni, and there is no signal peak of Cr-Ni in the X-ray photoelectron spectroscopy (XPS). Using polydopamine as carbon source, 3D graphene was prepared on stainless steel surface nano-pore arrays with pore sizes of 50nm and 240nm, respectively. The biosafety of NIH-3T3 fibroblasts in vitro was evaluated. The biocompatibility of 316L stainless steel was improved by nano-pore array. Three-dimensional graphene causes cytotoxicity, and the toxicity is related to its three-dimensional configuration. The toxicity is caused by the cell phagocytosis of nano-carbon spheres in the three-dimensional graphene layer, which hinders the synthesis of adhesion proteins and actin filaments. Eventually leading to apoptosis.
【学位授予单位】：武汉科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG174.4;R318.08

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