The regeneration of injured tendons and ligaments is challenging because the scaffolds needs proper mechanical properties and a biomimetic morphology. In particular, the morphological arrangement of scaffolds is a key point to drive the cells growth to properly regenerate the collagen extracellular matrix. Electrospinning is a promising technique to produce hierarchically structured nanofibrous scaffolds able to guide cells in the regeneration of the injured tissue. Moreover, the dynamic stretching in bioreactors of electrospun scaffolds had demonstrated to speed up cell shape modifications in vitro. The aim of the present study was to combine different imaging techniques such as high‐resolution X‐ray tomography (XCT), scanning electron microscopy (SEM), fluorescence microscopy and histology to investigate if hierarchically structured poly (L‐lactic acid) and collagen electrospun scaffolds can induce morphological modifications in human fibroblasts, while cultured in static and dynamic conditions. After 7 days of parallel cultures, the results assessed that fibroblasts had proliferated on the external nanofibrous sheath of the static scaffolds, elongating themselves circumferentially. The dynamic cultures revealed a preferential axial orientation of fibroblasts growth on the external sheath. The aligned nanofibre bundles inside the hierarchical scaffolds instead, allowed a physiological distribution of the fibroblasts along the nanofibre direction. Inside the dynamic scaffolds, cells appeared thinner compared with the static counterpart. This study had demonstrated that hierarchically structured electrospun scaffolds can induce different fibroblasts morphological modifications during static and dynamic conditions, modifying their shape in the direction of the applied loads.

中文翻译：

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分层静电纺丝腱韧带仿生支架在静态和动态条件下诱导成纤维细胞形态的变化

受伤的肌腱和韧带的再生具有挑战性，因为支架需要适当的机械性能和仿生形态。特别是支架的形态排列是驱动细胞生长以正确再生胶原细胞外基质的关键点。静电纺丝是一种很有前途的技术，可以生产分层结构的纳米纤维支架，能够在受伤组织的再生过程中引导细胞。此外，电纺支架生物反应器中的动态拉伸已证明可以加速体外细胞形状的改变。本研究的目的是结合不同的成像技术，如高分辨率 X 射线断层扫描 (XCT)、扫描电子显微镜 (SEM)、荧光显微镜和组织学研究分层结构的聚（L-乳酸）和胶原电纺支架是否可以在静态和动态条件下培养时诱导人成纤维细胞的形态学改变。平行培养 7 天后，结果评估成纤维细胞在静态支架的外部纳米纤维鞘上增殖，沿圆周拉长自身。动态培养物显示成纤维细胞在外鞘上的优先轴向生长。相反，分级支架内对齐的纳米纤维束允许成纤维细胞沿纳米纤维方向进行生理分布。在动态支架内，与静态对应物相比，细胞显得更薄。