Whulanza Y, Arafat Y B, Rahman S F, Utomo M S, Kassegne S
Department of Mechanical Engineering, Faculty of Engineering, Universitas Indonesia, Indonesia.
Research Center on Biomedical Engineering, Universitas Indonesia, Indonesia.
Heliyon. 2022 May 16;8(5):e09445. doi: 10.1016/j.heliyon.2022.e09445. eCollection 2022 May.
It is known that excessive concentrations of glutamate in the brain can cause neurotoxicity. A common approach to neutralizing this phenomenon is the use of suppressant drugs. However, excessive dependence on suppressant drugs could potentially lead to adversarial side effects, such as drug addiction. Here, we propose an alternative approach to this problem by controlling excessive amounts of glutamate ions through carbon-based, neural implant-mediated uptake. In this study, we introduce a microfluidic system that enables us to emulate the uptake of glutamate into the carbon matrix. The uptake is controlled using electrical pulses to incorporate glutamate ions into the carbon matrix through electro-adsorption. The effect of electric potential on glutamate ion uptake to control the amount of glutamate released into the microfluidic system was observed. The glutamate concentration was measured using a Ultra Violet-Visible spectrophotometer. The current setup demonstrated that a low pulsatile electric potential (0.5-1.5 V) was able to effectively govern the uptake of glutamate ions. The stimulated carbon matrix was able to decrease glutamate concentration by up to 40%. Furthermore, our study shows that these "entrapped" glutamate molecules can be effectively released upon electrical stimulation, thereby reversing the carbon electrical charge through a process called reverse uptake. A release model was used to study the profile of glutamate release from the carbon matrix at a potential of 0-1.5 V. This study showed that a burst release of glutamate was evident at an applied voltage higher than 0.5 V. Ultimately, the MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) test for cytotoxicity indicated a cell viability of more than 80% for the carbon matrix. This test demonstrates that the carbon matrix can support the proliferation of cells and has a nontoxic composition; thus, it could be accepted as a candidate material for use as neural implants.
众所周知，大脑中谷氨酸浓度过高会导致神经毒性。中和这种现象的常见方法是使用抑制药物。然而，过度依赖抑制药物可能会导致不良副作用，如药物成瘾。在此，我们提出一种解决该问题的替代方法，即通过基于碳的神经植入介导摄取来控制过量的谷氨酸离子。在本研究中，我们引入了一种微流体系统，该系统使我们能够模拟谷氨酸被碳基质摄取的过程。通过电吸附利用电脉冲将谷氨酸离子纳入碳基质来控制摄取过程。观察了电势对谷氨酸离子摄取的影响，以控制释放到微流体系统中的谷氨酸量。使用紫外可见分光光度计测量谷氨酸浓度。当前的实验装置表明，低脉冲电势（0.5 - 1.5伏）能够有效控制谷氨酸离子的摄取。受刺激的碳基质能够使谷氨酸浓度降低多达40%。此外，我们的研究表明，这些“捕获”的谷氨酸分子在电刺激下能够有效释放，从而通过一种称为反向摄取的过程使碳电荷反转。使用释放模型研究了在0 - 1.5伏电势下谷氨酸从碳基质释放的情况。该研究表明，在高于0.5伏的施加电压下，谷氨酸会出现突发释放。最终，用于细胞毒性的MTS（3 -（4,5 - 二甲基噻唑 - 2 - 基） - 5 -（3 - 羧甲氧基苯基） - 2 -（4 - 磺基苯基） - 2H - 四唑）测试表明，碳基质的细胞活力超过80%。该测试表明碳基质能够支持细胞增殖且成分无毒；因此，它可被视为用作神经植入物的候选材料。
