Scaffolds prepared by 3D printing are increasingly used in the field of bone tissue repair. However, on traditional 3D printed bone tissue engineering scaffolds, cells can only grow on the fiber surface and form bone. We designed a scaffold with a cross-scale structure of PCL/β-TCP, which contains thick fibers with a diameter of 500 μm printed by FDM. And in the pores of the coarse fiber, the ultra-high precision fine fiber grid with a diameter of about 10 μm is filled by MEW mode. In cell experiments, cells can not only grow on the thick fiber surface of the cross-scale scaffold. At the same time, the mesh structure of fine fibers provides a bridge for cell growth, allowing cells to pass through the pores of thick fibers and grow in the pores and gradually cover the pores of the scaffold. In the osteoinduction experiment, β-TCP in the PCL/β-TCP composite provides Ca²⁺ and PO₄³⁻ to the scaffold, which effectively promotes the osteogenic differentiation of cells on the scaffold. Compared with traditional scaffolds, the osteogenic performance of cross-scale scaffolds is greatly improved. Not only did bone form on the surface of the scaffold, but also obvious ALP expression and effective calcium precipitation appeared in the pores of the scaffold. This can effectively speed up the repair of bone defects. We believe that the 3D printed PCL/β-TCP cross-scale scaffold with high-precision fibers has great application prospects in the field of bone tissue engineering.

通过3D打印制备的支架在骨组织修复领域中越来越多地被使用。但是，在传统的3D打印骨骼组织工程支架上，细胞只能在纤维表面生长并形成骨骼。我们设计了一种具有PCL /β-TCP交叉尺度结构的支架，该支架包含FDM打印的直径为500μm的粗纤维。并且在粗纤维的孔中，通过MEW模式填充直径约10μm的超高精度细纤维网格。在细胞实验中，细胞不仅可以在横尺度支架的粗纤维表面上生长。同时，细纤维的网状结构为细胞生长提供了桥梁，使细胞穿过粗纤维的孔并在孔中生长并逐渐覆盖支架的孔。在骨诱导实验中²⁺和PO ₄ ^3-进入支架，可有效促进支架上细胞的成骨分化。与传统支架相比，跨尺度支架的成骨性能大大提高。不仅在支架表面上形成骨，而且在支架的孔中也出现了明显的ALP表达和有效的钙沉淀。这样可以有效地加快骨缺损的修复。我们相信具有高精度纤维的3D打印PCL /β-TCP跨尺度支架在骨组织工程领域具有广阔的应用前景。