浸润性可调的纳米ZnO表面蛋白吸附规律及其在蛋白分离中的应用

发布时间：2018-02-27 08:37

  本文关键词： 纳米ZnO 浸润性 蛋白吸附 蛋白分离　出处：《东北师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：纳米ZnO作为一种具有优异光电性能和良好生物相容性的半导体纳米材料,在荧光成像、生物检测等诸多生物医学领域中体现出了巨大的应用潜力。在加快其实用化进程中,Zn O与生物物质界面间相互作用的研究尤为重要。大量研究表明固体表面浸润性是影响纳米生物界面性质的重要因素之一。虽然纳米ZnO表面浸润性已有研究,但是其对蛋白吸附行为的调控却鲜有报道。蛋白在固体表面的吸附还将进一步影响细胞的粘附,因此,系统研究纳米ZnO表面浸润性对蛋白吸附的影响规律并建立相关模型有助于加深ZnO与生物物质作用机制的理解,为新型、高效纳米生物医用平台的发展提供理论与技术支持。本论文以浸润性可调的纳米ZnO为研究对象,探究了蛋白与细胞在其表面吸附/粘附规律,并以此为基础,改进了传统的蛋白磁分离技术,开发了基于超疏水纳米ZnO界面的高效痕量蛋白分离技术。具体研究内容如下:1.利用紫外光辐射和暗态存储等方式调节了纳米ZnO表面浸润性,获得了一系列从超亲水到超疏水的纳米ZnO。以牛血清白蛋白(BSA)为模型蛋白,系统研究了纳米ZnO表面浸润性对BSA吸附行为的影响。研究结果表明,由于蛋白吸附位点随ZnO亲水性增强而增加,因此,BSA在纳米ZnO表面的吸附量也随之增加。BSA吸附动力学测试及红外光谱表征证实了BSA在纳米ZnO表面存在着吸附、脱附与构象变化三个过程。BSA吸附与脱附速率随ZnO表面疏水性的增强而增大,这可能与键联在ZnO表面的水分子氢键网络产生的能量势垒有关。BSA构象变化速率随纳米ZnO疏水性增强而增大,但当ZnO表面达到超疏水时,该速率略有减小,这可能是BSA与ZnO间疏水相互作用增强和吸附位点减小共同导致的结果。软蛋白BSA在具有不同浸润性的纳米ZnO表面的吸附规律还适用于硬蛋白(如溶菌酶蛋白)吸附及细胞(如4T1细胞)粘附。这一研究对加深纳米生物界面作用机制的理解及纳米生物界面材料的选择、设计和应用提高了重要的理论和实验参考。2.选用纳米ZnO作为痕量蛋白磁分离器壁材料,研究其表面浸润性对蛋白分离效率的影响。研究结果表明,蛋白分离效率随蛋白浓度的降低而减小,蛋白在超疏水纳米ZnO上的分离效率优于普通商用的塑料、玻璃基底和疏水纳米ZnO,尤其在蛋白浓度较低时(≤200μg/mL),超疏水纳米ZnO分离效率更具明显优势。疏水纳米ZnO蛋白分离效率低于商用材料,证实了提高痕量蛋白分离效率的关键因素是材料表面浸润性,而非化学组成。超疏水纳米ZnO蛋白分离效率还与蛋白种类有关,硬蛋白分离回收效率较软蛋白来说更高。该超疏水ZnO表面适用于分离pH为6.0~8.0,离子强度为0~1mol/mL的痕量蛋白体系的分离。该研究结果为改进现有痕量蛋白磁分离技术提供了新思路。
[Abstract]:Nanocrystalline ZnO is a kind of semiconductor nanomaterials with excellent optoelectronic properties and good biocompatibility in fluorescence imaging. Many biomedical fields, such as biological detection, have shown great application potential. It is particularly important to study the interaction between Zno and biomaterial interface in accelerating the practical process. A large number of studies show that solid surface infiltration. Property is one of the most important factors affecting the properties of nanoscale biological interface. Although the surface wettability of nanocrystalline ZnO has been studied, However, the regulation of protein adsorption behavior is rarely reported. The adsorption of protein on solid surface will further affect cell adhesion. A systematic study of the effect of surface wettability on protein adsorption of nanometer ZnO and the establishment of related models will help to deepen the understanding of the mechanism of interaction between ZnO and biomaterials, which is a new type of protein adsorption. The development of high efficiency nano-biomedical platform provides theoretical and technical support. In this paper, we study the adsorption / adhesion of protein and cell on the surface of ZnO. In this paper, the traditional protein magnetic separation technique is improved, and the high efficiency trace protein separation technology based on superhydrophobic nanometer ZnO interface is developed. The specific research contents are as follows: 1. The surface wettability of nanometer ZnO is regulated by ultraviolet radiation and dark state storage. A series of nanocrystalline ZnOs from superhydrophilic to superhydrophobic were obtained. Using bovine serum albumin (BSA) as model proteins, the effects of surface wettability of ZnO on the adsorption behavior of BSA were systematically studied. Because the protein adsorption sites increase with the increase of the hydrophilicity of ZnO, the adsorption capacity of BSA on the surface of nano-BSA is also increased. The adsorption kinetics of BSA on the surface of nano-BSA and the characterization of IR spectra confirm the existence of BSA adsorption on the surface of nano-#en3#. Desorption and conformation change. The adsorption and desorption rate of BSA increases with the increase of hydrophobicity of ZnO surface. This may be related to the energy barrier generated by the hydrogen bond network of water molecules on the surface of ZnO. The conformational change rate of ZnO increases with the increase of hydrophobicity of ZnO nanoparticles, but decreases slightly when the surface of ZnO reaches superhydrophobicity. This may be the result of the enhancement of hydrophobic interaction between BSA and ZnO and the decrease of adsorption sites. The adsorption of soft protein BSA on the surface of nano-sized ZnO with different wettability can also be applied to the absorption of hard protein (such as lysozyme protein). Adhesion to cells (such as 4T1 cells). This study is intended to deepen the understanding of the mechanism of nanoscale biological interface and the selection of nanoscale biomaterials. The design and application improved the important theoretical and experimental reference. 2. Using nanometer ZnO as the wall material of trace protein magnetic separator, the effect of surface wettability on protein separation efficiency was studied. The separation efficiency of protein decreased with the decrease of protein concentration, and the separation efficiency of protein on superhydrophobic nanometer ZnO was better than that of ordinary commercial plastics. The separation efficiency of superhydrophobic nano-ZnO on glass substrate and hydrophobic nano-ZnO, especially when the protein concentration is lower (鈮，

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