天然高分子的手性功能化修饰与抗菌应用

发布时间：2018-02-26 12:12

本文关键词： 龙脑纤维素壳聚糖抑菌材料立体化学　出处：《北京化工大学》2015年硕士论文　论文类型：学位论文

【摘要】：一直以来,细菌在材料表面的粘附、增殖与随后形成的生物膜对人们的健康构成了严重的威胁。现有的抗菌材料大多是通过固定或释放杀菌剂来进行杀菌,在应用方面还有一定的局限性。基于细胞可以识别材料表面不同的手性分子信号,我们设计通过共价键将手性龙脑这种药物分子接枝到天然高分子(纤维素和壳聚糖)表面,用以在微生物接触材料的初期就产生抑制细菌粘附的效果,防止生物膜的形成。由于材料主要是依靠其自身的表面立体化学结构影响细菌识别表面分子信号来产生抑菌效果,因而推测不会促使细菌进化产生耐药性。龙脑、纤维素、壳聚糖都是天然产物,接枝改性后的复合高分子无细胞毒性,它们也不会对环境造成污染。本文首次通过共价键将L-龙脑接枝到纤维素表面,从而得到龙脑接枝纤维素(BGC)抑菌材料,通过一系列的表征对高分子结构进行了测定,证明BGC目标产物成功合成,接枝率17%。微生物实验研究表明,BGC材料对微生物有着良好的抗粘附和抑制生长的作用。主要的研究成果如下：1.BGC材料具有广谱抑真菌性能,如总状毛霉、黑曲霉、酵母等都不会在材料上粘附生长。2.BGC材料的抑菌时效可达8天以上,微观形态学研究发现真菌的孢子在材料上呈现休眠状态。3.BGC材料主要是应用龙脑小分子的立体化学结构在微生物粘附的初期产生抑菌作用。4.BGC材料具有良好的生物相容性,其细胞毒性与天然纤维素几乎一致,是一种没有生物毒性的材料,可用于医用敷料、食品包装等。同时,本文通过席夫碱键将L-龙脑接枝到羟乙基壳聚糖表面得到了一种龙脑功能化羟乙基壳聚糖(BFC)抑菌材料。微生物实验研究表明,BFC材料在细菌数量少时呈现抗细菌粘附功效,当细菌数量多时,呈现一定的杀菌功效。主要研究成果如下：1.BFC材料具有广谱抑菌性能,如黑曲霉、大肠杆菌等都不会在材料上粘附生长。2.BFC材料对霉菌有着很强的抑菌性能,其抑菌时间可达到29天,微观形态学研究发现霉菌在BFC材料表面不会萌发,并且BFC材料表面会使细菌产生形变、死亡。3.通过BFC材料修饰导尿管的研究模型,我们发现BFC材料对大肠杆菌的生长抑制作用可达67 cell/cm2。4.BFC材料面对少量菌时主要呈现阻止微生物粘附生长的状态；当遭遇大量细菌时,席夫碱键发生断裂,释放部分龙脑小分子以及溶出一定量的羟乙基壳聚糖,这使得材料不仅具有阻止微生物粘附生长的作用,还对微生物有着良好的杀菌潜力。
[Abstract]:The adhesion, proliferation and subsequent biofilm formation of bacteria on the surface of materials have been a serious threat to human health. Most of the existing antimicrobial materials are used to sterilize by immobilization or release of fungicides. Because cells can recognize different chiral molecular signals on the surface of materials, we designed to graft chiral borneol molecules onto the surface of natural polymers (cellulose and chitosan) by covalent bonds. It is used to inhibit bacterial adhesion and prevent biofilm from forming in the early stage of microorganism contact material. Because the material mainly depends on its surface stereochemical structure to influence the bacteria recognition surface molecular signal to produce bacteriostasis effect. Therefore, it is speculated that bacteria will not evolve to develop resistance. Borneol, cellulose and chitosan are all natural products, and the modified composite polymer is not cytotoxic. L- borneol was grafted onto cellulose surface by covalent bond for the first time to obtain borneol graft cellulose BGC-) bacteriostasis material, and the macromolecule structure was determined by a series of characterization. It was proved that the target product of BGC was successfully synthesized and the grafting rate was 17%. The microbiological experiment showed that the BGC material had good anti-adhesion and inhibitory effect on microorganism. The main research results were as follows: 1. BGC material has broad spectrum fungicidal inhibition properties, such as total Mucor, the main results of which are as follows: 1. Aspergillus Niger, yeast and so on do not adhere to growth on the material. 2. The bacteriostatic effect of BGC material can reach more than 8 days. Micromorphological study showed that the spores of fungi were dormant on the material. 3. The biocompatibility of BGC material was good by using the stereochemical structure of small molecule of borneol to produce bacteriostatic effect at the initial stage of microbial adhesion. Its cytotoxicity is almost the same as natural cellulose, it is a non-biotoxic material, can be used in medical dressings, food packaging, etc. At the same time, In this paper, a borneol functionalized hydroxyethyl chitosan (BFCC) antibacterial material was obtained by grafting L- borneol onto the surface of hydroxyethyl chitosan by Schiff base bond. The main research results are as follows: 1. BFC materials have broad spectrum bacteriostatic properties, such as Aspergillus Niger and Escherichia coli do not adhere to the material growth. 2. BFC materials have strong bacteriostasis to mold. The bacteriostasis time was up to 29 days. The micromorphological study showed that the mold did not germinate on the surface of BFC, and the surface of BFC made bacteria deform. 3. The model of catheter modification by BFC. We found that BFC could inhibit the growth of Escherichia coli as much as 67 cell/cm2.4.BFC, and the Schiff base bond was broken when a large number of bacteria were encountered. The release of some small borneol molecules and the dissolution of a certain amount of hydroxyethyl chitosan make the materials not only prevent the growth of microbes adhesion but also have a good bactericidal potential.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R318.08

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