The objective of this work was to fabricate a rigid, resorbable and osteoconductive scaffold by mimicking the hierarchical structure of the cortical bone. Aligned peptide-functionalize nanofiber microsheets were generated with calcium phosphate (CaP) content similar to that of the natural cortical bone. Next, the CaP-rich fibrous microsheets were wrapped around a microneedle to form a laminated microtube mimicking the structure of an osteon. Then, a set of the osteon-mimetic microtubes were assembled around a solid rod and the assembly was annealed to fuse the microtubes and form a shell. Next, an array of circular microholes were drilled on the outer surface of the shell to generate a cortical bone-like scaffold with an interconnected network of Haversian- and Volkmann-like microcanals. The CaP content, porosity and density of the bone-mimetic microsheets were 240 wt%, 8% and 1.9 g/ml, respectively, which were close to that of natural cortical bone. The interconnected network of microcanals in the fused microtubes increased permeability of a model protein in the scaffold. The cortical scaffold induced osteogenesis and vasculogenesis in the absence of bone morphogenetic proteins upon seeding with human mesenchymal stem cells and endothelial colony-forming cells. The localized and timed-release of morphogenetic factors significantly increased the extent of osteogenic and vasculogenic differentiation of human mesenchymal stem cells and endothelial colony-forming cells in the cortical scaffold. The cortical bone-mimetic nature of the cellular construct provided balanced rigidity, resorption rate, osteoconductivity and nutrient diffusivity to support vascularization and osteogenesis.

中文翻译：

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仿骨皮质骨样支架的材料和再生特性。


这项工作的目的是通过模仿皮质骨的分层结构来制造刚性、可吸收和骨传导支架。生成的对齐肽功能化纳米纤维微片的磷酸钙 (CaP) 含量与天然皮质骨相似。接下来，将富含 CaP 的纤维微片包裹在微针周围，形成模仿骨结构的层压微管。然后，将一组仿骨微管组装在一根实心棒周围，并对组件进行退火以融合微管并形成外壳。接下来，在外壳的外表面上钻出一系列圆形微孔，以生成具有哈弗斯和福克曼式微管互连网络的皮质骨样支架。仿骨微片的CaP含量、孔隙率和密度分别为240 wt%、8%和1.9 g/ml，接近天然皮质骨的含量。融合微管中相互连接的微管网络增加了支架中模型蛋白的渗透性。在缺乏骨形态发生蛋白的情况下，在接种人间充质干细胞和内皮集落形成细胞后，皮质支架诱导成骨和血管生成。形态发生因子的局部和定时释放显着增加了皮质支架中人间充质干细胞和内皮集落形成细胞的成骨和血管分化程度。细胞结构的皮质骨模拟性质提供了平衡的刚性、吸收率、骨传导性和营养扩散性，以支持血管形成和成骨。