壳聚糖电纺丝形成机制及其药物释放行为的研究
文献类型：学位论文
| 作者 | 徐芃 |
| 学位类别 | 硕士 |
| 答辩日期 | 2012-05-15 |
| 授予单位 | 中国科学院研究生院 |
| 导师 | 刘会洲 ; 李伟 |
| 关键词 | 静电纺丝 纳米纤维 机制研究 药物缓释 结构纤维 |
| 其他题名 | Electrospun chitosan nanofibers formation mechanism and their drug delivery behaviors |
| 学位专业 | 化学工艺 |
| 中文摘要 | 静电纺丝技术是一种制备超细纤维的方法，在许多领域具有应用潜力。但是由于静电纺丝过程复杂，并且静电纺丝机理尚不够明确，因此很难制备具有特殊功能、结构可控的纳米纤维。据此，本论文从静电纺丝出发，利用原子力显微镜，开展一系列有关静电纺丝机制的研究。本论文运用原子力显微镜考察了静电纺丝过程中纳米纤维结构的演变过程，并研究了不同溶液性质对静电纺丝结构变化的影响，进而首次提出了基于微观结构变化的静电纺丝形成机理。证实了静电纺丝过程不是纤维直径减小的单一过程，纤维表面还存伴随一系列结构变化：柱体结构、层状结构、多孔结构、突起结构和平滑表面。这有利于科研人员更进一步了解静电纺丝的形成机制，并且以后续制备具有特殊结构纳米纤维提供理论依据。在以上研究的基础上，对静电纺丝过程对纳米纤维表面孔结构的影响进行了研究，比较了不同电导率的纺丝液的纳米纤维表面孔结构的变化过程。结构表明，随着电导率的增大，孔的平均直径对深度的变化速度减小，并且孔边缘在垂直方向的生长增强。证实了静电纺丝过程对纤维孔结构的生成有非常重要的作用，具体体现在直接作用用纺丝表面的静电力和的作用。为了研究壳聚糖/聚环氧乙烯和聚乳酸/壳聚糖电纺丝载药纤维的药物释放行为，用原子力显微镜原位观察了这两种纤维在模拟体液PBS中的纤维结构分解情况。并结合药物释放曲线和浸泡不同时间后纤维膜分解情况的SEM图，发现壳聚糖/聚环氧乙烯纤维和聚乳酸/壳聚糖纤维具有不同的药物释放机制。壳聚糖/聚环氧乙烯载药纤维的药物释放主要是通过纤维结构的快速分解，BSA扩散作用相对较弱。而聚乳酸/壳聚糖纤维在溶液中未观测到有明显的分解，其药物释放机制可能主要是依靠BSA的扩散。除此之外，本论文对静电纺丝装置进行了改造，并利用纳米纤维在静电纺丝过程中特殊的飞行轨迹，制备出了具有螺纹结构的壳聚糖/聚环氧乙烯纳米纤维、聚乳酸纳米纤维和聚氨酯纳米纤维。 |
| 英文摘要 | Electrospinning is a valid technique to produce ultra fine fibers, which has potential applications in many fields. However, it is hard for researchers to obtain nanofibers with desired structures or functions, because the mechanism of nanofibers formation is still unclear and the process of electrospinning is complex. Hence, to figure out how the nanofibers formed, we investigated the mechanism of electrospinning with atomic force microscope (AFM). The structural evolution of nanofibers in electrospinning was studied by using AFM, and the effects of polymer solution properties on the process were also investigated. The mechanism of electrospinning was proposed based on microscopic point of view firstly. We demonstrated that electrospinning was not just a process of fiber thinning, which involved a series of structure variations, including five stages in turn: columns, plates, micropores, bumps and smoothness. The results not only helped us further understand the mechanism of electrospinning, but also might provide guidance to structured nanofibers production. Porous nanofibers were investigated for years for their wonderful characteristics. The effects of electrospinning on micropores formation were studied by contrasting the micropores variations of solution with different conductivity. Results showed that the decrease of diameter was hindered and the growth of micropores edges increased, when the conductivity was high. It proved that the process of electrospinning had important effects on micropores formation, more specifically, the electrostatic forces and directly influenced that surface structures of nanofibers. The drug delivery behaviors of CS-PEO nanofibers and PLA-CS nanofibers were studied by AFM. We compared that drug release curves and SEM images of nanofibe after different dissolving time, and found that CS-PEO nanofibers had different drug release mechanism than PLA-CS nanofibers. The drug release of CS-PEO nanofibers was controlled by structure degradation, while the drug diffusion was the secondary effect. On the contrary, PLA-CS nanofibers released the drugs by drug diffusion process, and the structure of PLA-CS nanofibers seldom degraded even after 30 days. In addtion, CS-PEO nanofibers, PLA nanofibers and PU nanofibers with whorl surface were successfully fabricated by a reformed electrospinning setup and the specific path of nanofibers in instability region was utilized to realize the structure of whorl. |
| 语种 | 中文 |
| 公开日期 | 2013-09-25 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1868]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 徐芃. 壳聚糖电纺丝形成机制及其药物释放行为的研究[D]. 中国科学院研究生院. 2012. |
入库方式： OAI收割
来源：过程工程研究所
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