State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China.
NMPA Key Laboratory for Research and Evaluation of Additive Manufacturing Medical Devices, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China.
Small. 2023 May;19(19):e2207331. doi: 10.1002/smll.202207331. Epub 2023 Feb 12.
Electrohydrodynamic (EHD) printing provides unparalleled opportunities in fabricating microfibrous architectures to direct cellular orientation. However, it faces great challenges in depositing orderly microfibers with cell-scale spacing due to inherent fiber-fiber electrostatic interactions. Here a finite element method is established to analyze the electrostatic forces induced on the EHD-printed microfibers and the relationship between the fiber diameter and spacing for parallel deposition of EHD-printed microfibers is revealed theoretically and experimentally. It is found that uniform fiber arrangement can be achieved when the fiber spacing is five times larger than the fiber diameter. This finding enables the successful printing of parallel fibrous architectures with a fiber diameter of 4.9 ± 0.1 µm and a cell-scale fiber spacing of 25.6 ± 1.9 µm. The resultant microfibrous architectures exhibit unique capability to direct cellular alignment and enhance cellular density and migration as the fiber spacing decreases from 100 to 25 µm. The EHD-printed parallel microfibers with cell-scale spacing are found to improve the outgrowth length of neurites and accelerate the migration of Schwann cells from Dorsal Root Ganglion spheres, which facilitate the formation of densely-arranged and highly-aligned cellular constructs. The presented method is promising to produce biomimetic microfibrous architectures for functional nerve regeneration.
静电纺丝（EHD）打印为制造微纤维结构以引导细胞取向提供了无与伦比的机会。然而，由于纤维间的固有静电相互作用，它在沉积具有细胞尺度间距的有序微纤维方面面临着巨大的挑战。在这里，建立了有限元方法来分析 EHD 打印微纤维上诱导的静电力，以及理论和实验揭示了 EHD 打印微纤维平行沉积的纤维直径和间距之间的关系。结果发现，当纤维间距是纤维直径的五倍时，可以实现均匀的纤维排列。这一发现使得成功打印具有 4.9 ± 0.1 µm 纤维直径和 25.6 ± 1.9 µm 细胞尺度纤维间距的平行纤维结构成为可能。所得的微纤维结构具有独特的引导细胞排列和增强细胞密度和迁移的能力，因为纤维间距从 100 µm 减小到 25 µm。发现具有细胞尺度间距的 EHD 打印平行微纤维能够增加神经突的生长长度并加速施万细胞从背根神经节球体的迁移，从而促进密集排列和高度对齐的细胞结构的形成。所提出的方法有望用于生产仿生微纤维结构以促进神经功能再生。
