Recently, hydrogels have gained enormous interest in three-dimensional (3D) bioprinting toward developing functional substitutes for tissue remolding. However, it is highly challenging to transmit electrical signals to cells due to the limited electrical conductivity of the bioprinted hydrogels. Herein, we demonstrate the 3D bioprinting-assisted fabrication of a conductive hydrogel scaffold based on poly-3,4-ethylene dioxythiophene (PEDOT) nanoparticles (NPs) deposited in gelatin methacryloyl (GelMA) for enhanced myogenic differentiation of mouse myoblasts (C2C12 cells). Initially, PEDOT NPs are dispersed in the hydrogel uniformly to enhance the conductive property of the hydrogel scaffold. Notably, the incorporated PEDOT NPs showed minimal influence on the printing ability of GelMA. Then, C2C12 cells are successfully encapsulated within GelMA/PEDOT conductive hydrogels using 3D extrusion bioprinting. Furthermore, the proliferation, migration and differentiation efficacies of C2C12 cells in the highly conductive GelMA/PEDOT composite scaffolds are demonstrated using various in vitro investigations of live/dead staining, F-actin staining, desmin and myogenin immunofluorescence staining. Finally, the effects of electrical signals on the stimulation of the scaffolds are investigated toward the myogenic differentiation of C2C12 cells and the formation of myotubes in vitro. Collectively, our findings demonstrate that the fabrication of the conductive hydrogels provides a feasible approach for the encapsulation of cells and the regeneration of the muscle tissue.

中文翻译：

---

导电水凝胶的 3D 生物打印可增强生肌分化


最近，水凝胶在三维（3D）生物打印领域引起了极大的兴趣，以开发组织重塑的功能替代品。然而，由于生物打印水凝胶的电导率有限，将电信号传输到细胞非常具有挑战性。在此，我们展示了基于聚 3,4-乙烯二氧噻吩 (PEDOT) 纳米颗粒 (NP) 沉积在明胶甲基丙烯酰 (GelMA) 中的导电水凝胶支架的 3D 生物打印辅助制造，用于增强小鼠成肌细胞（C2C12 细胞）的生肌分化。最初，PEDOT NPs均匀分散在水凝胶中，以增强水凝胶支架的导电性能。值得注意的是，掺入的 PEDOT NP 对 GelMA 的印刷能力影响极小。然后，使用 3D 挤出生物打印将 C2C12 细胞成功封装在 GelMA/PEDOT 导电水凝胶内。此外，通过活/死染色、F-肌动蛋白染色、结蛋白和肌细胞生成素免疫荧光染色的各种体外研究，证明了高导电性 GelMA/PEDOT 复合支架中 C2C12 细胞的增殖、迁移和分化功效。最后，研究了电信号对支架刺激的影响，以促进 C2C12 细胞的肌原性分化和体外肌管的形成。总的来说，我们的研究结果表明，导电水凝胶的制造为细胞封装和肌肉组织再生提供了一种可行的方法。