【作者】 周文娟；

【导师】 李世普；

【作者基本信息】 武汉理工大学 ， 生物医学工程， 2002， 硕士

【摘要】 聚乳酸(PLA)因其良好的生物相容性、生物可降解性以及良好的可塑性而被广泛地应用于组织工程支架材料的研究，但是单一的聚乳酸长期在培养液或机体内因降解而易导致局部炎性反应。 本论文主要研究了PDLLA／HA组织工程复合支架材料的制备和性能。其中包括PDLLA／HA复合纤维的成型和性能测试以及PDLLA／HA无纺网的制备和细胞培养。 选用熔融纺丝法制备PDLLA／HA复合纤维，探索了熔融纺丝过程中温度、挤出机转速、拉伸速率、加料速度和冷却速率等一系列工艺参数的选择及其影响因素。通过研究发现温度是影响熔融纺丝的关键因素，熔融纺丝较适宜的条件是：温度为100～150℃，挤出机转速为10～15r／min，拉伸速率为2～5m/min。 对纤维的力学性能进行测试，研究了HA的含量、PDLLA的分子量、纤维的直径以及加工成型的温度等对PDLLA／HA复合纤维力学性能的影响规律。通过研究发现，分子量为1.529×10~5，HA含量为10％，直径为30～40μm的PDLLA／HA复合纤维抗张强度可达767.06MPa，初始膜量可达0.27GPa。 通过对试样的性能测试和形貌观察，研究了PDLLA／HA复合纤维在降解过程中其分子量、重量和力学性能以及缓冲溶液pH值等一系列参数的变化规律，并探讨了复合纤维的降解机理。结果表明复合纤维的降解属于简单本体水解，并呈现“双态降解”模型，纤维中心的降解比表面快。前期降解较为缓慢，pH值基本稳定地保持在7.0左右，HA真正起到了代偿PDLLA降解引起的pH下降的作用，有助于防上无菌性炎症的发生，也有利于细胞生长和组织形成。 将15～30μm的PDLLA／HA复合纤维制作成一定结构的无纺网，经包埋后进行软骨细胞培养，分析不同的包埋剂对软骨细胞吸附、形态利功能的影响。发现采用Ⅰ型胶原蛋白，鼠尾胶原蛋白和多聚赖氨酸包埋的PDLLA／HA无纺网均有促进软骨细胞粘附、增殖、分化和产生基质的作用。这三种包埋剂之间无明显差异，但均优于无包埋情况。研究表明，PDLLA／HA无纺网是一种性能优良的细胞培养支架材料。更多还原

【Abstract】 Poly(lactic acid)(PLA) has been widely used as scaffolds for tissue engineering because of its good processability, good biocompatibility and suitable mechanical properties. But its catabolite would often induce erythrophlogosis.The preparation and properties of the PDLLA/HA compound fiber and cell culture on the PDLLA/HA unwoven meshes had research researched in this paper.PDLLA/HA composite fibers were produced by melt spinning, and the choices of the process parameters such as temperature, revolving speed and drawing speed etc were discussed. It was suitable for melt spinning that temperature was 100~150 ℃, revolving speed was 10~15r/min and drawing speed was 2~5m/min.The influence of the content of HA, molecular weight of PDLLA and the diameter of fibers on the mechanical properties of PDLLA/HA composite fiber had been studied through mechanical tests. The tensile strength of composite fiber could reach 767.06MPa and the tensile modulus could reach 0.27GPa when molecular weight of PDLLA was 1.529×105, content of HA was 10% and the diamter of fibers was 30~40μm.The changes in molecular weight, mass, mechanical strength, microstructure of fibers and pH value of the buffer solution with time in vitro had been studied. The study shows that degradation mechanism of PDLLA/HA compound fiber was indicative of an autocatalysis process and simple noumenon hydrolysis. It presentes the modal of "bimorph degradation".Unwoven meshes were formed by PDLLA/HA composite fibers with diameter of 10~ 15μm and embedded by I collagen albumen, polylysine and collagen albumen of the rats’ tails. It was found that these three different embedded scaffolds could promote adhesion, proliferation, differentiation and matrix secretion of the cells. There was no obvious difference among them, but all of them were more excellent than unembedded one.更多还原