Luo Cenyi, Xue Juan, Huang Qingyi, Deng Yuxiang, Zhao Zhixin, Li Jiafeng, Gao Xiaoyan, Li Zhengqiu
School of Material Science and Engineering, Xihua University, Chengdu 610039, China.
CCTEG Coal Mining Research Institute, Beijing 100013, China.
Biomolecules. 2025 Jul 25;15(8):1075. doi: 10.3390/biom15081075.
This study proposes a continuous preparation strategy for poly (l-lactic acid) (PLLA) scaffolds with oriented hierarchical microporous structures for bone repair. A PLLA-oriented multi-stage microporous bone repair scaffold (hereafter referred to as the oriented multi-stage microporous scaffold) was designed using a novel extrusion foaming technology that integrates fused deposition modeling (FDM) 3D printing with supercritical carbon dioxide (SC-CO) microcellular foaming technology. The influence of the 3D-printed structure on the microcellular morphology of the oriented multi-stage microporous scaffold was investigated and optimized. The combination of FDM and SC-CO foaming technology enables a continuous extrusion foaming process for preparing oriented multi-stage microporous scaffolds. The mechanical strength of the scaffold reached 15.27 MPa, meeting the requirements for bone repair in a low-load environment. Notably, the formation of open pores on the surface of the oriented multi-stage microporous scaffold positively affected cell proliferation, differentiation, and activity, as well as the expression of anti-inflammatory and pro-inflammatory factors. In vitro cell experiments (such as CCK-8) showed that the cell proliferation rate in the oriented multi-stage microporous scaffold reached 100-300% after many days of cultivation. This work provides a strategy for the design and manufacture of PLLA scaffolds with hierarchical microcellular structures and biocompatibility for bone repair.
本研究提出了一种用于骨修复的具有定向分级微孔结构的聚（L-乳酸）（PLLA）支架的连续制备策略。采用一种新颖的挤出发泡技术设计了一种PLLA定向多级微孔骨修复支架（以下简称定向多级微孔支架），该技术将熔融沉积建模（FDM）3D打印与超临界二氧化碳（SC-CO）微孔发泡技术相结合。研究并优化了3D打印结构对定向多级微孔支架微孔形态的影响。FDM和SC-CO发泡技术的结合实现了制备定向多级微孔支架的连续挤出发泡过程。支架的机械强度达到15.27MPa，满足低负荷环境下骨修复的要求。值得注意的是，定向多级微孔支架表面开孔的形成对细胞增殖、分化和活性以及抗炎和促炎因子的表达产生了积极影响。体外细胞实验（如CCK-8）表明，经过多日培养后，定向多级微孔支架中的细胞增殖率达到100%-300%。这项工作为设计和制造具有分级微孔结构和生物相容性的用于骨修复的PLLA支架提供了一种策略。
