高分子三维多孔生物支架的成型及结构性能研究

发布时间：2018-03-04 17:37

本文选题：高分子生物工程支架　切入点：三维多孔结构　出处：《郑州大学》2012年博士论文　论文类型：学位论文

【摘要】：组织工程多孔生物支架作为种植细胞的场所和组织再生的模板,是组织工程领域重要研究方向之一,已经引起了越来越多的研究者重视。理想的多孔生物支架必须具备,高孔隙率、内部相互连通性、无毒性、良好的生物相容性和较好力学性能等,因此,如何制备符合及满足细胞需求的理想三维多孔生物支架是组织工程领域的前沿课题。基于可降解高分子生物支架具有在引导细胞生长的同时可被机体吸收的突出优点,使其成为生物支架研究方向的热点。论文以可降解高分子生物支架的制备工艺一结构形态一性能为主线,通过选择合适的加工方法、设计合理的材料配方,调控泡孔形态、孔隙率、吸水率、内部连通性和力学性能等,加工制备新型的具有高孔隙率且内部相互连通的三维多孔可降解高分子生物支架。主要工作包括： 1、采用注塑成型／粒子沥滤技术加工PCL和PCL/HA三维多孔生物支架。基于不同材料配方控制支架的泡孔形态、孔隙率、力学性能、吸水性能和生物性能。分析NaCl颗粒和可溶性高分子聚合物PEO的沥滤过程,对比探讨了PCL和PCL/HA三维多孔生物支架的力学性能和生物相容性。研究结果表明,PEO的应用较大的提高了支架内部相互连通性；HA的使用不仅增强了支架的力学性能,而且促进了细胞的增殖生长。 2、利用微发泡注塑成型/粒子沥滤技术加工PCL三维多孔生物支架。对比探究了传统注塑成型和微发泡注塑成型技术所制备支架的内部孔洞结构形态、静态和动态力学性能、孔隙率和吸水率等。超临界N2的使用不仅作为物理发泡剂,而且起到增塑剂的作用,降低共混物的熔体粘度,使其易于加工成型,同时有效的提高了PCL生物支架的孔隙率。 3、基于注塑成型技术、弱酸沥滤方法和新材料配方(PCL/PEO/NaCl/壳聚糖纤维),首次利用壳聚糖纤维加工了具有微孔洞和微管道双重形态特征的三维多孔PCL生物支架。壳聚糖纤维的引入,不仅在支架中形成了微管道结构形态,而且提高了其孔隙率及内部连通性。分析了壳聚糖含量对PCL生物支架泡孔形态和力学性能影响。 4、采用单向冷冻干燥法和静电纺丝技术相结合,加工了具有微米级管道和纳米级微结构特征的高孔隙率三维壳聚糖/PLGA纳米复合生物支架。相比壳聚糖生物支架,PLGA纳米纤维的加入不仅使三维生物支架具有纳米级形态结构,而且使其具有较大的比表面积和更高的力学性能。并研究了壳聚糖溶液浓度和静电纺丝时间对支架结构形态和力学性能的影响。 5、研究了压缩成型聚酸酐样品的降解机理和降解速率。分析探究了样品加工温度和几何尺寸对其降解速率的影响。
[Abstract]:Tissue engineering porous scaffold, as a template for cell implantation and tissue regeneration, is one of the important research directions in the field of tissue engineering, and has attracted more and more researchers' attention. High porosity, internal connectivity, non-toxicity, good biocompatibility and good mechanical properties, etc. How to prepare ideal three-dimensional porous scaffolds that meet and meet the needs of cells is a leading issue in tissue engineering. Based on the outstanding advantages of biodegradable polymer scaffolds, they can be absorbed by the body while guiding cell growth. It has become a hot spot in the research direction of biological scaffolds. In this paper, the preparation process of biodegradable polymer scaffolds, structure, morphology and properties are taken as the main line. By selecting suitable processing methods, a reasonable material formulation is designed to regulate the bubble morphology, porosity and water absorption. New three dimensional porous biodegradable polymer scaffolds with high porosity and interconnectedness are fabricated by internal connectivity and mechanical properties. The main work includes:. 1. PCL and PCL/HA three-dimensional porous biological scaffolds were fabricated by injection molding / particle leaching technology. The bubble morphology, porosity and mechanical properties of the scaffolds were controlled based on different material formulations. Water absorption and biological properties. Analysis of leaching process of NaCl particles and soluble polymer PEO, The mechanical properties and biocompatibility of PCL and PCL/HA three-dimensional porous scaffolds were compared and discussed. The results showed that the application of PCL/HA not only enhanced the mechanical properties of scaffolds, but also improved the internal connectivity of the scaffolds. And promote cell proliferation and growth. 2. Microfoaming injection molding / particle leaching technology was used to process PCL three-dimensional porous biological scaffolds. The internal pore structure, static and dynamic mechanical properties of the scaffolds prepared by conventional injection molding and micro-foaming injection molding were compared. The use of supercritical N2 is not only used as a physical foaming agent but also as a plasticizer to reduce the melt viscosity of the blend and make it easy to be processed and molded. At the same time the porosity of the PCL biological scaffold is improved effectively. 3. Based on injection molding technology, weak acid leaching method and new material formula, PCL / PEO / NaCl / chitosan fiber was used for the first time to process three-dimensional porous PCL biological scaffolds with dual morphology of micropores and microtubes. Not only the microtube structure was formed in the scaffold, but also the porosity and internal connectivity were improved. The effect of chitosan content on the bubble morphology and mechanical properties of PCL biological scaffold was analyzed. (4) unidirectional freeze-drying method and electrostatic spinning technology, Three dimensional chitosan / PLGA nanocomposite scaffolds with high porosity and microstructures were fabricated. Compared with chitosan scaffolds, the addition of PLGA nanofibers not only made the three-dimensional scaffolds have nanoscale morphology. The effects of concentration of chitosan solution and electrostatic spinning time on the structure morphology and mechanical properties of the scaffold were studied. 5. The degradation mechanism and degradation rate of compression formed polyanhydride samples were studied, and the effects of sample processing temperature and geometric size on the degradation rate were analyzed.
【学位授予单位】：郑州大学
【学位级别】：博士
【学位授予年份】：2012
【分类号】：R318.08

【共引文献】