Martins Patrícia Alexandra, Barroca Nathalie, Vieira Sandra I, de Sousa Bárbara M, Gil Guilherme, Cicuéndez Mónica, Casarrubios Laura, Feito María José, Diez-Orejas Rosalía, Portolés Maria Teresa, Figueiredo Bruno, Silva Rui, Garcia-Lizarribar Andrea, Fonseca Pedro, Alves Luís Nero, Marques Paula A A P
Centre for Mechanical Technology Automation (TEMA), Department of Mechanical Engineering, University of Aveiro Aveiro Portugal
Department of Electronics, Telecommunications and Informatics, University of Aveiro Aveiro Portugal.
RSC Adv. 2025 Sep 1;15(38):31257-31271. doi: 10.1039/d5ra02570b. eCollection 2025 Aug 29.
Notwithstanding the demonstrated benefits of electrical stimulation in enhancing tissue functionality, existing state-of-the-art electrostimulation systems often depend on invasive electrodes or planar designs. This work exploits the versatility of graphene to fabricate biocompatible electrodes for the three-dimensional electrical stimulation of neural stem cells. A conductive green graphene-based ink was formulated and screen-printed as the bottom and top electrodes in a bottom-less standard culture well plate. Upon exposure to macrophages, although some oxidative stress was observed, this graphene-based ink did not elicit an increase in the pro-inflammatory cytokine IL-6. An analysis of the electrode impedance as a function of time and frequency was performed to optimize the 3D electrical stimulation. The efficacy of these graphene electrodes for electrically stimulating cells across 3D environments was investigated in scaffolds composed of a decellularized extracellular matrix and reduced graphene oxide, which had previously shown the capability to facilitate neuronal differentiation and to create a pro-regenerative microenvironment . Neural stem cells were seeded on these scaffolds and electrically stimulated with a 10 Hz bidirectional current signal of 200 μA for 1 hour daily. At the target frequency of 10 Hz, deemed advantageous for neural regeneration, a scaffold impedance below 800 Ω was ensured. The low-frequency 3D stimulation proved to enhance cellular mechanisms essential for the development of neuronal networks, including neuronal differentiation, neuritogenesis and neurite growth.
尽管电刺激在增强组织功能方面已显示出诸多益处，但现有的先进电刺激系统通常依赖侵入性电极或平面设计。这项工作利用石墨烯的多功能性来制造用于对神经干细胞进行三维电刺激的生物相容性电极。配制了一种基于绿色石墨烯的导电墨水，并将其丝网印刷在无底标准培养孔板中作为底部和顶部电极。在与巨噬细胞接触后，虽然观察到了一些氧化应激，但这种基于石墨烯的墨水并未引起促炎细胞因子IL - 6的增加。进行了电极阻抗随时间和频率变化的分析，以优化三维电刺激。在由脱细胞细胞外基质和还原氧化石墨烯组成的支架中研究了这些石墨烯电极在三维环境中电刺激细胞的功效，该支架先前已显示出促进神经元分化和创造促再生微环境的能力。将神经干细胞接种在这些支架上，每天用200 μA的10 Hz双向电流信号电刺激1小时。在被认为有利于神经再生的10 Hz目标频率下，确保支架阻抗低于800 Ω。低频三维刺激被证明可增强神经网络发育所必需的细胞机制，包括神经元分化、神经突形成和神经突生长。
