光州科学技术大学的研究人员开发具有可调寿命的可注射生物电极

植入式生物电极是一种电子设备，可以通过向活生物系统传输信号来监测或刺激生物活动。这种装置可以使用各种材料和技术制造。但是，由于它们与活组织的密切接触和相互作用，选择合适的性能和生物相容性材料至关重要。近年来，可导电水凝胶因其柔韧性、相容性和优异的相互作用能力而作为生物电极材料受到广泛关注。然而，传统导电水凝胶中缺乏可注射性和降解性限制了其在生物系统中的使用便利性和性能。

在此背景下，韩国研究人员现已开发出具有可注射性和可调降解性的石墨烯基导电水凝胶，进一步推动了先进生物电极的设计和开发。该研究由光州科学技术大学（GIST）的Jae Young Lee教授领导，并于2023年2月24日发表在《小型》杂志上。

李教授在解释他们研究的基本原理时说：“传统的植入式电极经常引起几个问题，例如植入的大切口和体内不受控制的稳定性。相比之下，导电水凝胶材料允许微创递送和控制生物电极的功能在体内寿命，因此非常需要。

为了合成可注射导电水凝胶（ICHs），研究人员使用硫醇官能化的还原氧化石墨烯（F-rGO）作为导电组分，因为它具有较大的表面积和优异的电气和机械性能。他们选择了二马来酰亚胺（PEG-2Mal）和二丙烯酸酯（PEG-2Ac）官能化的聚乙二醇作为预聚物，以促进分别稳定和可水解的ICHs的开发。然后将这些预聚物与聚（乙二醇）-四硫醇（PEG-4SH）和F-rGO进行硫醇-烯反应。

用PEG-2Ac制成的ICH是可降解的（DICH），而用PEG-2Mal制成的ICH是稳定的（SICH）。研究人员发现，新型ICHs通过与组织结合非常好并记录最高信号而优于各种现有ICHs。在体外条件下（在生物体外），SICH一个月没有降解，而DICH从第三天开始逐渐降解。

当植入小鼠皮肤时，DICH在给药三天后消失，而SICH保持其形状长达7天。除了可控的降解性外，两种ICHs都与皮肤相容。

此外，研究小组评估了ICHs在大鼠肌肉和皮肤中记录体内肌电图信号的能力。SICH和DICH都记录了高质量的信号，并超越了传统金属电极的性能。SICH记录可以监测长达三周，而DICH信号在五天后完全丢失。这些发现表明，SICH电极适用于长期信号监测，而DICH电极适用于不需要手术切除的临时使用。

总结这些结果，Lee教授说：“我们开发的新型石墨烯基ICH电极具有高信号灵敏度，使用简单，最小侵入性和可调降解性等特点。总之，这些特性可以帮助开发先进的生物电子学和功能性植入式生物电极，用于各种医疗条件，如神经肌肉疾病和神经系统疾病。

我们当然希望这一发展能很快迎来一个治疗和诊断进步的新时代！

Reference

DOI: https://doi.org/10.1002/smll.202300250

Authors: Junggeon Park¹, Sanghun Lee¹, Mingyu Lee¹, Hyung-Seok Kim², and Jae Young Lee¹

Affiliations:

¹School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST)

²Department of Forensic Medicine, Chonnam National University Medical School

About the Gwangju Institute of Science and Technology (GIST)
The Gwangju Institute of Science and Technology (GIST) is a research-oriented university situated in Gwangju, South Korea. Founded in 1993, GIST has become one of the most prestigious schools in South Korea. The university aims to create a strong research environment to spur advancements in science and technology and to promote collaboration between international and domestic research programs. With its motto of “A Proud Creator of Future Science and Technology,” GIST has consistently received one of the highest university rankings in Korea.

Website: http://www.gist.ac.kr/

About Professor Jae Young Lee
Jae Young Lee is a Professor at the School of Materials Science and Engineering and Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST), Republic of Korea. Dr. Lee received his B.S. and M.S. degrees in Chemical Technology from Seoul National University in 1997 and 1999, respectively. He then worked as a research manager in LG Life Science Ltd from 1999 to 2005. He received his Ph.D. from The University of Texas at Austin, USA in 2010 and did his postdoctoral research at UC Berkeley as a recipient of the American Heart Association postdoctoral fellowship. He joined GIST in 2012. His research interests include designs of electrically conductive biomaterials, drug/cell delivery, and nano-biomaterials for tissue regeneration.