构建具有仿生细胞外基质结构的取向支架能有效促进各向异性组织的修复和重建，但目前多数取向结构只能在支架表面形成，限制了细胞的三维生长，不利于组织修复。虽然单轴冷冻干燥技术能制备三维取向微管支架，但微管间连通率低，不利于细胞接种和均匀分布，而且制备过程中使用大量的有机溶剂会损害支架的生物相容性。本项目拟采用“熔融挤出-热拉伸”技术提供的强可控拉伸流动场，诱导共连续共混物（其中一相为水溶性聚合物）发生相取向变形；之后，萃取水溶性高分子相，获得具有三维取向连通结构的多孔支架。系统研究共混物种类、分子量、比例及拉伸条件诱导取向共连续相形态和结构的影响规律；基于此，指导“熔融挤出-热拉伸”过程中的结构调控，揭示构筑取向相及取向连通孔的机理，获得制备取向连通多孔支架的临界加工条件。将支架的微观结构与宏观力学性能和生物学性能相关联，建立“加工-结构-性能”关系，为制备高性能取向多孔支架提供理论和技术支持。

Constructing aligned porous scaffolds to imitate extracellular matrix could promote anisotropic tissue regeneration effectively. However, in most cases, the aligned structures only form on the surface of scaffolds, impeding spatial cell growth and thus being detrimental to tissue repair. Although a unidirectional freeze-drying technology was employed to prepare three-dimensional (3D) scaffolds with aligned microtubes, low interconnection between the parallel microtubes limited homogeneous cell seeding and distribution. Besides, large amount of organic solvent used in the fabrication process may jeopardize the biocompatibility of scaffolds. In this proposal, we plan to employ the “melting extrusion-hot stretching” technique to induce the oriented phase deformation of co-continuous blends (one phase is the water-soluble polymer) by exerting intense stretching field. Then, the interconnected aligned structure is generated in the 3D porous scaffolds after hydrosoluble phase removal. Systematic investigation will be performed on effects of polymer composition, molecular weight, proportion, and stretching conditions on the formation mechanism of aligned co-continuous phases. The above results could further guide structure evolution and control during the “melting extrusion-hot stretching”. We intend to reveal the formation mechanism of aligned phases and interconnected oriented pores, obtain the processing window of oriented porous scaffolds, and establish the correlation between microstructure with macroscopic mechanical and biological performance. Finally, the “processing-structure-performance” relationship of the aligned porous scaffolds is set up. The obtained fundamentals will offer theoretical guidelines and technical assistance for manufacturing aligned porous scaffolds with superior performance.