氧化再生纤维素钠盐可吸收止血纱的降解机制研究

发布时间：2018-04-21 04:54

本文选题：氧化再生纤维素钠盐 + 降解机制　；参考：《哈尔滨工业大学》2013年硕士论文

【摘要】：止血材料在医学技术快速发展的今天已经成为一种必不可少的手术用品，其种类繁多，氧化再生纤维素（ORC）止血材料是研究热点之一。将氧化再生纤维素经过氢氧化钠可控中和后得到的氧化再生纤维素钠盐（ORC-Na）是一种新型水溶性可吸收止血材料。与ORC相比，ORC-Na具有更快的止血速度，更广的应用范围等优势。本文主要是针对ORC-Na的研究降解规律和降解机制进行研究，提出最合适的贮存条件，从理论上对材料的降解进行分析。研究ORC-Na的降解规律时，主要针对降解时间、降解温度、降解环境、辐照灭菌剂量和包装方式对材料降解的影响。利用聚合度、酸碱度以及羧基含量对降解情况进行评价。结果表明，降解时间越长，温度越高，材料的聚合度越低，pH越低，羧基含量越少；在贮存环境中，空气和水对降解有促进作用；经过辐照灭菌后，材料的聚合度和羧基含量都会降低，但是降解不会随辐照剂量增加而增加；在不同的包装方式中，以氮气包装的降解程度最低。材料的体外降解研究表明，材料在14天后降解为小分子，通过高效液相色谱和视差折光检测器最终分析出产物为葡萄糖和葡萄糖醛酸。分析ORC-Na的降解机制，，对降解前后的材料进行结构测试。首先利用SEM、XPS研究降解前后材料表面的变化情况，结果表明：降解后ORC-Na单根纤维表面出现了裂纹，并且编织结构出现了整根断裂的情况；表面上氧和钠元素含量降低，推测有脱羧反应发生。红外光谱、紫外光谱和核磁共振结果表明：降解过程中材料的整体结构并没有发生很大的变化，材料结构中有共轭基团生成。在ORC-Na氧化过程中C-6上出现了酰基结构和芳杂环的二酮结构。利用硼氢化钠对降解后的ORC-Na进行还原，结果表明ORC-Na水溶液还原后颜色消失。利用过氧化氢对ORC-Na处理，材料恢复为降解前的白色。~(13)C固态核磁共振结果表明，过氧化氢将材料制备过程中的副产物酰基氧化成为羧基。采用模型化合物的研究方法，以1,2-环己二酮为模型化合物，最终得出结论，导致ORC-Na变黄的主要因素是材料制备过程引入的副产物烯醇和酮基构成的共轭结构。过氧化氢处理将ORC-Na中的烯醇结构氧化为酮基，进而破坏了结构中的共轭体系，使ORC-Na的颜色消失。对降解和过氧化氢氧化的样品进行止血试验，利用耳动脉模型和肝脏出血模型对止血时间和出血量进行研究，结果表明，过氧化氢处理降解后ORC-Na，对于材料的止血性能没有影响。
[Abstract]:With the rapid development of medical technology, hemostatic materials have become an indispensable surgical product. There are many kinds of hemostatic materials, and oxidized regenerated cellulose ORC (ORC) hemostatic materials are one of the research hotspots. The oxidized regenerated cellulose (ORC-Na) prepared by controlled neutralization of oxidized regenerated cellulose with sodium hydroxide is a new water-soluble absorbable hemostatic material. Compared with ORC, ORC-Na has the advantages of faster hemostatic speed and wider application range. In this paper, the degradation law and degradation mechanism of ORC-Na were studied, and the most suitable storage conditions were put forward, and the degradation of materials was analyzed theoretically. In order to study the degradation rule of ORC-Na, the effects of degradation time, degradation temperature, degradation environment, irradiation sterilization dose and packaging method on the degradation of ORC-Na were studied. The degree of polymerization, pH and carboxyl content were used to evaluate the degradation. The results showed that the longer the degradation time, the higher the temperature, the lower the polymerization degree, the lower the pH, the lower the carboxyl content and the less the carboxyl content. In the storage environment, air and water can promote the degradation. The degree of polymerization and carboxyl content of the materials will decrease, but the degradation will not increase with the increase of irradiation dose. Among the different packaging methods, nitrogen packaging has the lowest degradation degree. The degradation of the materials in vitro showed that the materials were degraded into small molecules after 14 days. The products were finally identified as glucose and glucuronic acid by high performance liquid chromatography and parallax refractive index detector. The degradation mechanism of ORC-Na was analyzed and the structure of the materials before and after degradation was tested. At first, the surface changes of ORC-Na fiber before and after degradation were studied by means of ORC-Na. The results showed that cracks appeared on the surface of ORC-Na single fiber and the braided structure was fractured, and the content of oxygen and sodium on the surface decreased. It was speculated that decarboxylation reaction occurred. The results of IR, UV and NMR showed that the whole structure of the material did not change greatly during the degradation process, and conjugated groups were formed in the structure of the material. Acyl groups and aromatic heterocyclic diketones were found on C-6 during ORC-Na oxidation. The degradation of ORC-Na was reduced by sodium borohydride. The results showed that the color of ORC-Na solution disappeared after reduction. After ORC-Na was treated with hydrogen peroxide, the results of solid-state NMR showed that the by-product acyl group was oxidized to carboxyl group by hydrogen peroxide. In this paper, the method of model compound was used. The conclusion was drawn that the main factor leading to the yellowing of ORC-Na was the conjugated structure of enol and ketone, which was introduced in the preparation of the material. The enol structure in ORC-Na was oxidized to ketone group by hydrogen peroxide treatment, which destroyed the conjugated system in the structure and made the color of ORC-Na disappear. The hemostatic test was carried out on the samples degraded and oxidized by hydrogen peroxide. The hemostatic time and the amount of bleeding were studied by ear artery model and hepatic hemorrhage model. The results showed that the treatment of hydrogen peroxide had no effect on the hemostatic performance of the materials.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R318.08

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