一种抗菌性胍基化壳聚糖材料的制备及其抗菌评价

发布时间：2018-02-02 19:33

本文关键词： 壳聚糖胍基乙酸化壳聚糖金黄色葡萄球菌大肠杆菌抗菌性能　出处：《华中科技大学》2012年硕士论文　论文类型：学位论文

【摘要】：壳聚糖(Chitosan,CS)是自然界中唯一已知的含氮碱性多糖，有良好的生物相容性、可降解性、抗菌性。壳聚糖及其衍生物在促进伤口愈合、抗菌和抗病毒等领域的应用日益引人注目。壳聚糖衍生物抗菌性能随其所带正电性增强而增大,胍基是目前发现的自然界正电性最强的有机基团，引入胍基基团能增强壳聚糖的抗菌性能。因而本文设计了一种抗菌性胍基化壳聚糖即胍基乙酸化壳聚糖（CS-N-Guanidine，CG），并测定壳聚糖及其胍基乙酸化壳聚糖的抗菌性能并得出相关结论。本文通过对甲壳素进行脱乙酰得到脱乙酰度较低的壳聚糖，再进行纯化、脱乙酰、分子量降解之后得到脱乙酰度为83.15%，分子量为80.4kDa的纯化壳聚糖。以EDC(1-(3-二甲氨基丙基)-3-乙基碳二亚胺)为引发剂，NHS(N-羟基硫代琥珀酰亚胺)为催化剂，MES(2-(N-吗啉)乙磺酸)为缓冲液将胍基乙酸接枝到纯化壳聚糖的自由氨基上得到胍基乙酸化壳聚糖，控制反应时间18h，24h，36h得到三种取代度分别为11.03%、13.39%、21.59%的胍基乙酸化壳聚糖。采用琼脂糖平板计数法测定胍基乙酸化壳聚糖对革兰氏阳性菌金黄色葡萄球菌（Staphylococcus aureus, S. aureus）和革兰氏阴性菌大肠杆菌（Escherichia coli，E. coli）的抑制作用。结果表明：CS和CG对金黄色葡萄球菌和大肠杆菌有抑制作用，且CG的抑制作用比CS明显，CG的抗菌性能随取代度的提高而增强。 CS在浓度＜0.3g/L时对金黄色葡萄球菌有微弱的促进作用，在浓度＞0.3g/L能够完全抑制金黄色葡萄球菌的生长；在浓度＜0.2g/L对大肠杆菌有微弱的促进作用，随着浓度的提高抑菌效果越来越明显，在浓度＞0.3g/L时能完全抑制大肠杆菌的生长。 CG在浓度＜0.15g/L时能够促进金黄色葡萄球菌的生长，，随浓度的提高抑菌性能也得到提高，且取代度越高，抑菌效果越明显，在浓度＞0.15g/L时金黄色葡萄球菌的生长完全受到抑制；CG在浓度＜0.1g/L时能促进大肠杆菌的生长，浓度＞0.1g/L时表现出抑制作用，且取代度越高抑制效果越明显，当浓度达到0.15g/L时可以完全抑制大肠杆菌的生长。
[Abstract]:Chitosan Chitosanine (CSS) is the only nitrogen-containing alkaline polysaccharide known in nature with good biocompatibility biodegradability and antibacterial properties. Chitosan and its derivatives promote wound healing. Antimicrobial and antiviral applications have become increasingly attractive. The antibacterial properties of chitosan derivatives increase with the increase of positive charge. Guanidine is the most active organic group found in nature. The introduction of guanidine groups can enhance the antibacterial properties of chitosan. Therefore, a kind of antimicrobial guanidine chitosan (CS-N-Guanidine CGG) was designed. The antimicrobial properties of chitosan and its guanidine acetate chitosan were determined and the relevant conclusions were obtained. In this paper, chitosan with low degree of deacetylation was obtained by deacetylation of chitin, then purified, deacetylated, and deacetylated to 83.15% after molecular weight degradation. A purified chitosan with molecular weight of 80.4 kDa was prepared by using EDCA (1-dimethylaminopropyl) -3-ethylcarbodiimide as initiator. NHSN-hydroxythiosuccinimide) was used as catalyst. The guanidinoacetic acid was grafted onto the free amino group of purified chitosan, and the reaction time was 18 h / 24 h. The degree of substitution was 11.03% and 13.39% respectively at 36h. 21.59% guanidine acetate chitosan. Agarose plate counting method was used to determine the effect of guanidine acetate chitosan on Gram-positive bacteria Staphylococcus aureus (Staphylococcus aureus). Staphylococcus aureus. The inhibitory effects of Saureus and Escherichia coli E. coli. The results showed that the inhibitory effect of CG on Staphylococcus aureus and Escherichia coli was more obvious than that of CS, and the antibacterial activity of CG increased with the increase of substitution degree. CS had a slight effect on Staphylococcus aureus when the concentration was less than 0.3 g / L, and could completely inhibit the growth of Staphylococcus aureus when the concentration was more than 0.3 g / L. The bacteriostatic effect of Escherichia coli was more and more obvious when the concentration was less than 0.2 g / L, and the growth of Escherichia coli could be completely inhibited when the concentration was more than 0.3 g / L. CG could promote the growth of Staphylococcus aureus when the concentration of CG was less than 0.15 g / L, and the higher the degree of substitution, the more obvious the bacteriostatic effect was. The growth of Staphylococcus aureus was completely inhibited when the concentration was more than 0.15 g / L. CG could promote the growth of Escherichia coli when the concentration was less than 0.1 g / L, and when the concentration was higher than 0.1 g / L, the inhibitory effect was more obvious, and the higher the degree of substitution was, the more obvious the inhibitory effect was. When the concentration reached 0.15 g / L, the growth of Escherichia coli was completely inhibited.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318.08

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