Joshi Akshat, Choudhury Saswat, Majhi Arabinda, Parasuram Sampath, Baghel Vageesh Singh, Chauhan Samrat, Khanra Supriya, Lahiri Debrupa, Chatterjee Kaushik
Department of Bioengineering, Indian Institute of Science, C.V. Raman Avenue, Bangalore 560012, India.
Biomaterials and Multiscale Mechanics Lab, Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Roorkee 247667, India.
Biomater Sci. 2025 Aug 19;13(17):4706-4716. doi: 10.1039/d5bm00166h.
Conductive hydrogels are critical for advanced bioelectronics and the repair of electroactive tissues. However, developing conductive hydrogels into complex biomimetic shapes with good flexibility and bioactivity poses a major biofabrication challenge. This study utilizes dual-component hydrogel inks based on alginate incorporating conductive fCNT (acid-functionalized carbon nanotube) nanofillers, with the composite gel exhibiting an electrical conductivity of 6.6 ± 0.5 mS cm at 2 mg ml fCNT loading. Owing to their good combination of electrical conductivity and mechanical properties, the (three-dimensional) 3D-printed gels were successfully applied as strain sensors to sense subtle human motions, such as finger and elbow bending. Bilayered hydrogels prepared through four-dimensional (4D) printing exhibited programmable shape changes owing to differential swelling post-printing to yield nerve guidance conduits (NGCs) of intricate and tissue-adaptable designs, such as single and multichannel and bifurcated designs, based on accurate prediction by finite element analysis. The proliferation of neural cells was enhanced on the fCNT-gel compared to the neat gel. Sutureless deployment and enhanced peripheral nerve regeneration were established for the fCNT-gel in a rat sciatic nerve injury model. Overall, this work presents the fabrication of 4D-printed multifunctional conductive hydrogels, which can find diverse applications ranging from implantable nerve conduits to strain sensing.
导电水凝胶对于先进生物电子学和电活性组织的修复至关重要。然而，将导电水凝胶加工成具有良好柔韧性和生物活性的复杂仿生形状是生物制造面临的一项重大挑战。本研究利用基于藻酸盐并掺入导电fCNT（酸功能化碳纳米管）纳米填料的双组分水凝胶墨水，在fCNT负载量为2 mg/ml时，复合凝胶的电导率为6.6±0.5 mS/cm。由于其良好的导电性和机械性能组合，3D打印凝胶成功用作应变传感器来感知细微的人体运动，如手指和肘部弯曲。通过四维（4D）打印制备的双层水凝胶由于打印后不同程度的膨胀而呈现可编程的形状变化，从而基于有限元分析的精确预测生成复杂且适合组织的设计的神经引导导管（NGC），如单通道和多通道以及分叉设计。与纯凝胶相比，神经细胞在fCNT凝胶上的增殖得到增强。对于大鼠坐骨神经损伤模型中的fCNT凝胶，实现了无缝部署和增强的周围神经再生。总体而言，这项工作展示了4D打印多功能导电水凝胶的制造，其可在从可植入神经导管到应变传感等各种应用中找到用武之地。
