3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Avepark - Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017, Barco, Guimarães, Portugal.
ICVS/3B's-PT Associate Laboratory, Braga, Portugal.
Small. 2017 Aug;13(31). doi: 10.1002/smll.201700689. Epub 2017 Jun 20.
Tendon and ligament (T/L) function is intrinsically related with their unique hierarchically and anisotropically organized extracellular matrix. Their natural healing capacity is, however, limited. Here, continuous and aligned electrospun nanofiber threads (CANT) based on synthetic/natural polymer blends mechanically reinforced with cellulose nanocrystals are produced to replicate the nanoscale collagen fibrils grouped into microscale collagen fibers that compose the native T/L. CANT are then incrementally assembled into 3D hierarchical scaffolds, resulting in woven constructions, which simultaneously mimic T/L nano-to-macro architecture, nanotopography, and nonlinear biomechanical behavior. Biological performance is assessed using human-tendon-derived cells (hTDCs) and human adipose stem cells (hASCs). Scaffolds nanotopography and microstructure induce a high cytoskeleton elongation and anisotropic organization typical of tendon tissues. Moreover, the expression of tendon-related markers (Collagen types I and III, Tenascin-C, and Scleraxis) by both cell types, and the similarities observed on their expression patterns over time suggest that the developed scaffolds not only prevent the phenotypic drift of hTDCs, but also trigger tenogenic differentiation of hASCs. Overall, these results demonstrate a feasible approach for the scalable production of 3D hierarchical scaffolds that exhibit key structural and biomechanical properties, which can be advantageously explored in acellular and cellular T/L TE strategies.
肌腱和韧带（T/L）的功能与其独特的层次和各向异性组织的细胞外基质密切相关。然而，它们的自然愈合能力有限。在这里，我们使用基于合成/天然聚合物共混物的连续和定向电纺纳米纤维线（CANT），并通过纤维素纳米晶体进行机械增强，以复制组成天然 T/L 的纳米级胶原原纤维聚集而成的微级胶原纤维。然后，将 CANT 逐步组装成 3D 分层支架，形成编织结构，同时模拟 T/L 的纳米到宏观结构、纳米形貌和非线性生物力学行为。使用人肌腱源性细胞（hTDCs）和人脂肪干细胞（hASCs）评估生物性能。支架的纳米形貌和微观结构诱导出高度伸长的细胞骨架和典型的肌腱组织各向异性组织。此外，两种细胞类型都表达肌腱相关标志物（I 型和 III 型胶原、腱糖蛋白-C 和 Scleraxis），并且随着时间的推移观察到它们的表达模式相似，这表明所开发的支架不仅可以防止 hTDCs 的表型漂移，还可以触发 hASCs 的腱形成分化。总的来说，这些结果证明了一种可行的方法，可以大规模生产具有关键结构和生物力学特性的 3D 分层支架，这在无细胞和细胞 T/L TE 策略中可以得到有利的探索。
