纳米材料与抗生素联合作用的抗菌性能及机制研究

发布时间：2018-04-08 11:48

本文选题：纳米材料　切入点：细菌　出处：《上海大学》2015年硕士论文

【摘要】：现实生活中,纳米材料单独暴露的场合很少,更多是与其它化学物质同时存在。他们联合作用可能改变单独暴露时的生物效应,产生协同、拮抗等效应。因而研究纳米材料在复合体系中的生物效应及其作用机制具有重要的现实意义。目前,纳米银等材料,由于其优异的杀菌性能,已作为杀菌剂被广泛地应用于纺织品、医疗设备、包装材料和化妆品等诸多领域,在环境中广泛存在。同时,抗生素也被大量使用导致其在环境中普遍存在。作为一种新型环境污染物,它容易诱导病原菌产生耐药性,对人类健康和环境造成威胁。因此,在环境中纳米银等材料与抗生素极有可能共同存在。本论文选择典型的聚乙烯吡咯烷酮修饰的银纳米颗粒(Ag-PVP NPs)和常用抗生素为模型,研究它们联合暴露对细菌(大肠杆菌、金色葡萄球菌和耐庆大霉素大肠杆菌)的作用,探讨协同和拮抗体系的作用机制,继而选择协同作用的体系用于抗耐药细菌的研究,为抗菌剂的研发提供了新的思路。首先,通过测定Ag-PVP NPs与不同抗生素单独作用时的最小抑菌浓度,联合作用时的部分抑菌浓度指数,以及细菌的存活率和生长曲线获得两者联合作用对不同细菌菌株抗菌性能的影响。随后,利用活/死细菌染色,细菌形貌观察,元素含量测定和多种谱学技术深入研究Ag-PVP NPs与庆大霉素的联合体系与不同细菌的相互作用,包括庆大霉素对Ag-PVP NPs物化性质的影响。最后,利用紫外吸收光谱对Ag-PVP NPs与氨苄西林的相互作用进行初步研究。具体研究结果如下:(1)Ag-PVP NPs与抗生素联合暴露时,会产生包括协同,拮抗等多种作用结果。Ag-PVP NPs与庆大霉素联用表现为协同作用;与氨苄西林联用表现为拮抗作用;与青霉素G联用表现为无关或相加作用。与单独作用相比,Ag-PVP NPs与庆大霉素的联合作用能够增强其抗菌性能,使细菌的生长周期延迟和缩短,并且对庆大霉素耐药菌的抗菌效果也有大幅度提升。相反地,Ag-PVP NPs与氨苄西林的联合作用减弱了其抗菌性能。(2)Ag-PVP NPs和庆大霉素协同作用的联合体系主要是通过抑制细菌的生长和增殖而发挥抗菌效果的。庆大霉素对Ag-PVP NPs的溶解有促进作用,导致大量银离子的释放。同时,庆大霉素会增强Ag-PVP NPs与细菌的相互作用,致使细菌对银的摄取率提高。两方面的作用均会提升银的生物有效浓度,使联合体系产生协同抗菌作用。但庆大霉素与银离子的络合物却会削弱银离子本身的抗菌能力。因此联合体系的协同抗菌作用背后亦存在拮抗作用。(3)Ag-PVP能够吸附混合体系中的氨苄西林,导致体系中游离的氨苄西林的浓度下降,使抗菌效果减弱,联合体系表现为拮抗作用。另外,我们利用氧化石墨烯为原料,醋酸锌为锌源,无水乙醇为反应溶剂,通过简单的一步法制备得到了Zn O/GO纳米复合材料,并探究了复合材料的协同抗菌性能及机制,对复合材料的细胞毒性作出了评价。研究显示复合材料的抗菌活性远高于等量的Zn O纳米颗粒,抗菌能力存在浓度和时间依赖性,并且与GO片上的锌浓度密切相关。Zn O纳米颗粒在GO片上分布均匀,在GO包裹细菌时与细菌发生紧密接触和相互作用。另外,从Zn O纳米颗粒上溶解的锌离子会迅速吸附于GO片上,GO对细菌的包裹和覆盖作用使得细菌表面局部锌离子浓度显著提高,导致细胞膜受损,细菌形态改变,生长与繁殖受到抑制,最终死亡。Zn O/GO纳米复合材料在有效抗菌浓度下未表现出明显的细胞毒性,具有良好的生物相容性。本论文不仅获得了纳米材料在联合体系中的生物效应和作用机制方面的信息,拓展了纳米材料生物效应研究的广度与深度,并且关注联合作用的协同效应,为开发新型抗菌材料提供了新思路。
[Abstract]:In real life, nanomaterials exposed very few occasions, more is coexist with other chemicals. Their combined effects may alter the biological effect, separate exposure synergistic, antagonistic effect. So it has important practical significance to study the biological effects of nanomaterials in the composite system and its mechanism. At present, nano silver other materials, because of its excellent bactericidal properties, has been used as fungicides are widely used in textiles, medical equipment, packaging materials and cosmetics and other areas, is widespread in the environment. At the same time, antibiotics have been widely used due to its widespread presence in the environment. As a new type of environmental pollutants, it is easy to the pathogen induced resistance, pose a threat to human health and the environment. Therefore, the common existence in the environment of nano silver materials such as antibiotics and very likely. The anthology selection code Silver nanoparticle modified polyvinyl pyrrolidone (Ag-PVP NPs) and commonly used antibiotics as a model to study their combined exposure to bacteria (Escherichia coli, Staphylococcus aureus and gentamicin resistant Escherichia coli) role, to explore the mechanisms of synergistic and antagonistic system, then choose the synergy system for research of anti drug resistant bacteria and provide new ideas for the development of antibacterial agents. First of all, the minimal inhibitory concentration of Ag-PVP NPs alone with different antibiotics, the fractional inhibitory concentration index when combined, and the survival rate of bacteria and the growth curve for the combined effect of antibacterial properties of different bacterial strains. Subsequently, the use of live bacterial / dead staining, bacterial morphology, content determination and a variety of spectral combination system technology research of Ag-PVP NPs and gentamicin with different bacteria The role of Ag-PVP NPs, including the effect of gentamicin on physicochemical properties. Finally, the UV absorption spectra of interaction between Ag-PVP NPs and ampicillin were preliminarily studied. The main results are as follows: (1) Ag-PVP NPs combined with antibiotic exposure, will produce other effects including collaborative, antagonist NPs and gentamicin combined with.Ag-PVP results synergistically combined with ampicillin; antagonistic effect; and combined with penicillin G showed independent and additive effect. Compared with NPs alone, the combined effects of Ag-PVP and gentamicin can enhance its antibacterial properties, the growth cycle of bacteria and shorten the delay, and the antibacterial effect of gentamicin resistant bacteria is also large increase. On the contrary, the combined effect of Ag-PVP and NPs of ampicillin weakens its antibacterial properties. (2) Ag-PVP NPs and gentamicin synergistic combination system The growth and proliferation of bacteria and exert their antibacterial effect. The dissolution of gentamicin on Ag-PVP promoted NPs, resulting in a large number of silver ion release. At the same time, gentamicin will enhance the interaction of Ag-PVP and NPs bacteria, the bacteria on the silver uptake rate increased. The effective concentration of biological effect in two aspects will enhance the silver the unite system produces synergistic antibacterial effect. But the gentamicin and silver ion complexes but weakens the antibacterial ability of silver ion itself. Therefore, behind the synergic effects of joint system also has antagonistic effect. (3) Ag-PVP can be adsorbed in the mixed system of ampicillin, resulting in the concentration of free ampicillin decreased, the antibacterial the effect of reduced joint system showed antagonistic effect. In addition, we use graphene oxide as raw material, zinc acetate as zinc source, ethanol as solvent, by Jane A single step method of preparing Zn nano O/GO composite materials, and to explore the synergistic antibacterial properties and mechanism of composite materials, makes evaluation on the cytotoxicity of the composite material. The research shows that Zn O nanoparticle antibacterial activity of the composite is much higher than the equivalent, the antibacterial ability of concentration and time dependence, and closely related with the concentration of zinc on chip GO.Zn O nanoparticles were uniformly dispersed in the GO films, closely contact and interaction with bacteria in GO coated bacteria. In addition, the zinc ion Zn O nanoparticles on dissolved rapidly adsorbed on the GO chip, GO package and the covering effect on bacteria makes local zinc bacteria the surface of ion concentration increased significantly, resulting in cell membrane damage, bacterial morphology, growth and reproduction is inhibited, the final death of.Zn O/GO nano composite materials in effective antibacterial concentrations showed no obvious cytotoxicity, with Have a good biocompatibility. This paper not only obtained nano materials of biological effects in combined system and mechanism of information, expand the breadth and depth of research on biological effects of nanomaterials, and focus on the synergistic effect of combined effect, provides a new idea for the development of new antibacterial materials.

【学位授予单位】：上海大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1

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