柞蚕丝素蛋白的自组装及其在药物缓释上的应用

发布时间：2018-05-15 23:06

本文选题：柞蚕丝素 + 自组装　；参考：《东华大学》2012年硕士论文

【摘要】：柞蚕丝素是一种天然蛋白质,有良好的生物相容性及可降解性,常见其被应用在手术缝合线、软接触透镜、组织工程、伤口敷料以及药物缓释材料等方面,改变了柞蚕丝的传统应用。柞蚕丝素的降解产物对机体无毒,不易引起炎症和免疫排斥反应。鉴于这些特点,制作负载药物的微球及组织工程支架具有很好的医学应用前景。研究柞蚕丝素自组装及其在药物缓释方面的应用。分子自组装就是在平衡条件下,分子间通过非共价相互作用自发组合形成的一类结构明确、稳定、具有某种特定功能或性能的分子聚集体或超分子结构的过程。缓释控释给药系统是指在控释制剂的作用下药物按零级速率或接近恒速释放,以得到更平稳的血药浓度。在本论文的研究中,我们开发出了一种新颖的方法,使丝素蛋白在特定条件下通过自组装形成具有规整结构的蛋白基纳米微球和多孔支架材料,并对其临床医学应用进行了前期研究,主要内容是柞蚕丝素利用低毒无毒的溶剂诱导制备微球及多孔支架以及其在药物缓释上的应用。柞蚕丝素在乙醇的诱导及冷冻条件下制备柞蚕丝素微球,我们利用显微镜、场发射电镜、动态光散射、激光粒度仪、红外等仪器来测试自组装微球的形貌、粒径及内部结构,结果表明随着乙醇的增加,微球的粒径逐渐减小,结晶度相对提高,场发射电镜表明微球的表面是凸凹不平的结构。乙醇加入量为9ml时,平均粒径是184.52nm,分散指数0.2903,这是最理想的微球分布。采用扫描电镜观察了多孔支架的截面形态,具有规整的开孔式结构,空隙间相互贯通,具有较好的力学性能。多孔支架随柞蚕丝素溶液浓度的增加,其厚度增加,结晶度提高,孔径逐渐变得小而均匀,孔隙率高达80%,孔径在10～225μm之间。可塑性好的柞蚕丝素溶液制备的多孔支架由模具外形来决定其结构。柞蚕丝素溶液浓度大的构象转变程度变高,支架骨架的堆积也致密,丝素Ⅱ的成分增加,强度也有增大的趋势。随着浓度的增加,丝素Ⅱ的X-衍射角主要集中分布在17.2°,19.72°和29.42°。我们对自组装制备的丝素蛋白微球以及多孔支架在生物医药方面--药物缓释的应用进行了初步研究,明显延长了药物的释放时间。药物释放过程分为两个阶段：初期的快速释放阶段和后期的缓慢释放阶段,这就大大降低了临床药物的副作用,提高了药物的效率。5-Fu负载丝素蛋白多孔支架的药物负载率和载药率都略高于微球。柞蚕丝素自组装形成的微球和多孔支架在药物缓释方面具有很好的应用前景,为我们的后续研究提供了好的基础。
[Abstract]:Tussah silk fibroin is a natural protein, which has good biocompatibility and biodegradability. It is commonly used in surgical suture, soft contact lens, tissue engineering, wound dressing and drug release material. It has changed the traditional application of tussah silk. The degradation products of tussah silk fibroin are nontoxic to the body and are not easy to cause inflammation and immune rejection. In view of these characteristics, the preparation of loaded microspheres and tissue engineering scaffolds have good prospects for medical applications.
The self-assembly of tussah silk fibroin and its application in drug release. Molecular self-assembly is a process of molecular aggregation, stable, with certain specific functions or properties, formed by the spontaneous combination of non covalent interactions between molecules under equilibrium conditions. The release of the drug is controlled at zero or near constant speed to achieve a more stable blood concentration.
In this study, we developed a novel method to make silk fibroin protein based nanospheres and porous scaffolds with regular structure by self assembly under specific conditions, and to study the clinical application of silk fibroin. The main content is the preparation of tussah silk fibroin in the use of low toxicity and non-toxic solvent. Microspheres and porous scaffolds and their application in drug delivery.
Tussah silk fibroin was prepared under the conditions of ethanol induction and freezing to prepare tussah silk fibroin microspheres. We used microscopes, field emission electron microscopy, dynamic light scattering, laser particle size instrument, infrared and other instruments to test the morphology, particle size and internal structure of the self assembled microspheres. The results showed that the particle size of the microspheres decreased and the crystallinity increased with the increase of ethanol. The field emission electron microscope shows that the surface of the microspheres is a convex and concave structure. When the amount of ethanol is 9ml, the average particle size is 184.52nm and the dispersion index is 0.2903. This is the ideal microsphere distribution.
Scanning electron microscope (SEM) has been used to observe the cross section of porous scaffold, with a regular open hole structure with good mechanical properties. The thickness of porous scaffold increases with the concentration of tussah silk fibroin, its thickness increases, the pore size becomes smaller and even, the porosity is up to 80% and the pore size is 10~225 m. The structure of the porous scaffold prepared by the plastic silk fibroin solution is determined by the shape of the mold. The conformation transformation degree of the tussah silk fibroin solution is high, the accumulation of scaffold skeleton is also dense, the composition of silk fibroin II is increased and the strength of the silk fibroin II is increased. The X- diffraction angle of the silk fibroin II is mainly concentrated in 17.2 degrees, 19 .72 and 29.42 degrees.
A preliminary study of the application of self assembled silk fibroin microspheres and porous scaffolds in biopharmaceutical sustained-release was preliminarily studied, which significantly extended the release time of the drug. The drug release process was divided into two stages: the initial rapid release stage and the later slow release stage, which greatly reduced the clinical drug. Side effects enhanced the efficiency of drugs. The loading rate and drug loading rate of.5-Fu loaded porous silk fibroin scaffolds were slightly higher than that of microspheres.
The microspheres and porous scaffolds formed by self assembly of tussah silk fibroin have a good application prospect in drug delivery, and provide a good foundation for our follow-up research.

【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318.08

【参考文献】