Abstract：
The effective reconstruction of osteochondral biomimetic structures is a key factor in guiding the regeneration of full-thickness osteochondral defects. Due to the avascular nature of hyaline cartilage, the greatest challenge in constructing this scaffold lies in both utilizing the biomimetic structure to promote vascular differentiation for nutrient delivery to hyaline cartilage, thereby enhancing the efficiency of osteochondral reconstruction, and effectively blocking vascular ingrowth into the cartilage layer to prevent cartilage mineralization. However, the intrinsic relationship between the planning of the microporous pipe network and the flow resistance in the biomimetic structure, and the mechanism of promoting cell adhesion to achieve vascular differentiation and inhibiting cell adhesion to block the growth of blood vessels are still unclear. Inspired by the structure of tree trunks, this study designed a biomimetic tree-like tubular network structure for osteochondral scaffolds based on Murray\'s law. Utilizing computational fluid dynamics, the study investigated the influence of the branching angle of micro-pores on the flow velocity, pressure distribution, and scaffold permeability within the scaffold. The results indicate that when the differentiation angle exceeds 50 degrees, the highest flow velocity occurs at the confluence of tributaries at the ninth fractal position, forming a barrier layer. This structure effectively guides vascular growth, enhances nutrient transport capacity, increases flow velocity to promote cell adhesion, and inhibits cell infiltration into the cartilage layer.
摘要：
骨软骨仿生结构的有效重建是指导全层骨软骨缺损再生的关键因素。由于透明软骨的无血管性质，构建这种支架的最大挑战在于利用仿生结构促进血管分化，将营养输送到透明软骨，从而提高骨软骨重建的效率，并有效阻断血管向内生长进入软骨层，防止软骨矿化。然而,微孔管网规划与仿生结构中流动阻力的内在关系,促进细胞粘附以实现血管分化和抑制细胞粘附以阻断血管生长的机制尚不清楚。受树干结构的启发，本研究基于Murray定律设计了一种仿生树状骨软骨支架管状网络结构。利用计算流体动力学，研究了微孔的分支角对流速的影响,压力分布,和支架内的支架渗透性。结果表明,当微分角超过50度时,最高流速出现在第九分形位置的支流汇合处，形成阻挡层。这种结构有效地引导血管生长，增强养分转运能力，增加流速以促进细胞粘附，并抑制细胞渗入软骨层。
