二氧化钛及其复合纳米材料抗菌性能、作用机制的研究及应用

发布时间：2018-04-23 14:38

本文选题：二氧化钛 + 纳米颗粒　；参考：《暨南大学》2017年硕士论文

【摘要】：病原菌一旦在适宜的条件下,将会以指数方式增长,如何解除病原菌对人类的威胁,是一直以来研究的热点,从源头上控制病原菌的传播,减轻病菌的肆虐,是一条十分有效的路径。病原菌进入血液循环,产生毒素和其他代谢产物,危害人类健康和生命,导致数以百万计的人因为细菌感染而死亡。由于人类对抗生素的滥用,致使多药耐药菌感染问题日益严峻;临床应用的抗菌剂,通常存在着较严重的耐药性甚至过敏反应,开发新型抗菌材料成为迫切的需要。纳米材料由于表面积增大和晶格破损而产生特殊的物理化学性质,往往表现出令人意想不到的效果。纳米抗菌剂抗菌机理主要是:(1)与细菌内的遗传物质相结合,抑制DNA、RNA和蛋白质的合成,使细菌失活;(2)与细菌细胞膜相互作用,催化细菌细胞膜裂解,使细菌死亡;(3)与细菌菌体内的化学基团结合,使蛋白酶丧失活性,导致细菌死亡。纳米抗菌剂具有持久性、耐热性、生物相容性和不易产生耐药性等优点,受到科研界的广泛认可和高度重视。本研究分为以下三章:第一章:绪论,主要介绍了常见的引起细菌感染疾病的细菌菌种和对人类健康的影响,抗生素的历史及当今面临的困局,纳米医药在细菌感染方面的作用,最后重点介绍了二氧化钛纳米材料在抗菌方面的应用。第二章:采用自组装方法合成了氧化石墨烯-壳聚糖(GO@CS)薄膜,并将不同质量比例的二氧化钛(TiO2)负载在GO@CS薄膜上(GO:CS:TiO2内各组分的比例分别是1:20:2,1:20:4和1:20:8),进一步研究了TiO2在GO:CS:TiO2的含量对于抑制黑曲霉(A.niger)和枯草芽孢杆菌(B.subtilis)生长的影响。通过TEM图对GO:CS:TiO2上TiO2的分布及尺寸进行分析;通过菌落平板生长法、电导率法和考马斯亮蓝法、激光共聚焦法和扫描电子显微镜等研究了GO:CS:TiO2对黑曲霉和枯草芽孢杆菌的抗菌性能;通过测量草莓和芒果的多酚氧化酶和超氧化物歧化酶的变化,植物组织培养和动物细胞生物相容性验证了GO:CS:TiO2具有极好的生物相容性。其中,当GO:CS:TiO2的比例是1:20:4时,能够同时获得最佳的抗菌性能和生物相容性。我们相信,这些发现揭示了GO:CS:TiO2抗菌材料在应用方面的巨大的潜力。第三章:以大肠杆菌(E.coli)和金黄色葡萄球菌(S.aureus)为代表性的病原菌,对人类健康及经济环境造成巨大的威胁。为了控制这类病原菌的传播,减少危害,从源头上控制病原菌的增殖至关重要。有鉴于此,我们通过一种简易的方法,合成了二氧化钛-五氧化二钒(TiO2@V2O5)纳米抗菌剂。通过对TiO2进行改性,能够有效改善光敏性能,当与细菌菌膜相互作用时,能够产生活性氧使细菌菌膜发生损坏,从而起到抑菌作用。在本文中,我们通过一系列的表征,证明了TiO2@V2O5是一种分散均匀、稳定的球形纳米粒子,在光照下会产生光生电流,是一种良好的光敏材料;利用纸片法,测量菌液的OD值等实验,验证了TiO2@V2O5在光照下能够表现出极佳的抗菌性能,表明TiO2@V2O5的抗菌性能可能与光敏性能有一定的联系;一系列抗菌机理的研究则揭示了TiO2@V2O5在光照下能够产生以羟基自由基为主的活性氧,这是TiO2@V2O5能够产生抗菌性能的原因;动物相容性实验和植物相容性实验表明TiO2@V2O5对环境没有危害,证明了在未来大规模的应用中,具有巨大的潜力。
[Abstract]:Once the pathogen is in a suitable condition, it will grow exponentially. How to relieve the threat of pathogenic bacteria to human is a hot spot. It is a very effective way to control the spread of pathogenic bacteria and reduce the raging of pathogens from the source. The pathogen enters the blood circulation, produces toxins and other metabolites, and endangers people. Health and life lead to the death of millions of people because of bacterial infection. Because of the abuse of antibiotics, the problem of multidrug resistant bacteria is becoming increasingly serious; the antimicrobial agents in clinical application are usually more serious and even anaphylaxis, and the development of new antibacterial materials has become an urgent need. The special physical and chemical properties of the surface area and lattice damage often show an unexpected effect. The antibacterial mechanism of nanometers is mainly: (1) combining with the genetic material in the bacteria, inhibiting the synthesis of DNA, RNA and protein, inactivating the bacteria; (2) the interaction of the bacterial cell membrane and the catalytic cracking of the bacterial cell membrane To cause the death of bacteria; (3) to combine with the chemical groups in the bacteria to make the protease inactive and lead to the death of bacteria. The nano antibacterial agents have the advantages of persistence, heat resistance, biocompatibility and resistance to resistance to resistance. It is widely recognized and highly regarded by the scientific research community. This study is divided into the following three chapters: introduction, introduction, mainly introduced The common bacterial strains causing bacterial infection and the impact on human health, the history of antibiotics and the current dilemma, the role of nano medicine in bacterial infection. Finally, the application of titanium dioxide nanomaterials in the antibacterial field was introduced. The second chapter: the synthesis of graphene oxide shell polymerization by self assembly method. Sugar (GO@CS) films were loaded on GO@CS films with different mass ratios of titanium dioxide (TiO2) (1:20:2,1:20:4 and 1:20:8 in GO:CS:TiO2). The effects of TiO2 on the growth of Aspergillus niger (A.niger) and Bacillus subtilis (B.subtilis) were further investigated by TiO2 in GO:CS:TiO2. The distribution and size of the upper TiO2 were analyzed. The antibacterial properties of GO:CS:TiO2 against Aspergillus niger and Bacillus subtilis were studied by the method of colony plate growth, electrical conductivity method and Coomassie brilliant blue method, laser confocal method and scanning electron microscope, and the changes of polyphenol oxidase and superoxide dismutase in strawberry and mango were measured. Tissue culture and biocompatibility of animal cells verify that GO:CS:TiO2 has excellent biocompatibility. Among them, when the proportion of GO:CS:TiO2 is 1:20:4, the best antibacterial properties and biocompatibility can be obtained simultaneously. We believe that these discoveries reveal the great potential of the application of GO:CS:TiO2 antibacterial materials in the third chapter: Enterobacteriaceae (E.coli) and Staphylococcus aureus (S.aureus) are the representative pathogens that pose a great threat to human health and economic environment. In order to control the spread of this kind of pathogens and reduce the harm, it is very important to control the proliferation of pathogens from the source. Oxidation of two vanadium (TiO2@V2O5) nano antibacterial agent. By modifying the TiO2, it can effectively improve the photosensitivity. When interacting with the bacterial membrane, it can produce reactive oxygen (ROS) to damage the bacterial membrane and thus play a bacteriostasis effect. In this paper, we have proved that TiO2@V2O5 is a kind of homogeneous and stable dispersion through a series of characterization. Spherical nanoparticles can produce photocurrent under light, and it is a good photosensitive material. By using paper method to measure the OD value of bacterial liquid, it is proved that TiO2@V2O5 can show excellent antibacterial properties under light. It shows that the antibacterial properties of TiO2@V2O5 may be related to the photosensitivity, and a series of antibacterial mechanisms are studied. It is revealed that TiO2@V2O5 can produce reactive oxygen species based on hydroxyl radicals under light, which is the reason why TiO2@V2O5 can produce antibacterial properties. Animal compatibility and plant compatibility tests show that TiO2@V2O5 has no harm to the environment. It has great potential in large-scale applications in the future.

【学位授予单位】：暨南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R318.08

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