The design of hierarchical porous structure in scaffolds is crucial for bone defect regenerative repair. However, bioceramic materials present a challenge in precisely constructing designed micropores owing to the limitation of forming process. To investigate micropore shape influences bone regeneration in bioceramic scaffolds with macropores, hierarchical porous scaffolds with interconnective macropores (~400 μm) and two types of micropores (spherical and fibrous) were prepared using a combination of direct ink writing (DIW) and template sacrifice methods. Compared to the scaffold with spherical micropores, the scaffold with highly interconnected fibrous micropores significantly improved cell adhesion and upregulated osteogenic and angiogenetic-related gene expression in mBMSCs and HUVECs, respectively. Furthermore, in vivo implantation experiments showed that hierarchical scaffolds with fibrous micropores accelerated the bone repair process significantly. This result can be attributed to the high interconnectivity of fibrous micropores, which promotes the transportation of nutrients and waste during bone regeneration. Our work demonstrates that hierarchical porous scaffold design, especially one with a fibrous micropore structure, is a promising strategy for improving the bone regeneration performance of bioceramic scaffolds.

Graphical Abstract

中文翻译：

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具有合理设计的宏观-微观层次结构的 Beta-TCP 支架提高了骨再生的血管/成骨能力

支架中分层多孔结构的设计对于骨缺损的再生修复至关重要。然而，由于成型工艺的限制，生物陶瓷材料在精确构建设计的微孔方面面临挑战。为了研究微孔形状对大孔生物陶瓷支架骨再生的影响，采用直接墨水书写（DIW）和模板牺牲方法相结合制备了具有互连大孔（~400μm）和两种类型微孔（球形和纤维状）的分层多孔支架。与具有球形微孔的支架相比，具有高度互连的纤维微孔的支架分别显着改善了 mBMSC 和 HUVEC 中的细胞粘附并上调了成骨和血管生成相关基因的表达。此外，体内植入实验表明，具有纤维微孔的分层支架显着加速了骨修复过程。这一结果可归因于纤维微孔的高度互连性，促进骨再生过程中营养物质和废物的运输​​。我们的工作表明，分层多孔支架设计，尤其是具有纤维微孔结构的支架设计，是提高生物陶瓷支架骨再生性能的一种有前途的策略。

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