Department of Bioengineering, Imperial College London, London, SW7 2BX, UK.
Faculty of Medicine, Imperial College London, London, SW7 2BX, UK.
J Mater Chem B. 2024 Sep 18;12(36):8929-8940. doi: 10.1039/d4tb00679h.
Soft bioelectronic neural interfaces have great potential as mechanically favourable alternatives to implantable metal electrodes. In this pursuit, conductive hydrogels (CHs) are particularly viable, combining tissue compliance with the required electrochemical characteristics. Physically-aggregated CHs offer an additional advantage by their facile synthesis into injectable systems, enabling minimally invasive implantation, though they can be impeded by a lack of control over their particle size and packing. Guided by these principles, an injectable PEDOT:PSS/acetic acid-based hydrogel is presented herein whose mechanical and electrochemical properties are independently tuneable by modifying the relative acetic acid composition. The fabrication process further benefits from employing batch emulsion to decrease particle sizes and facilitate tighter packing. The resulting material is stable and anatomically compact upon injection both in tissue phantom and , while retaining favourable electrochemical properties in both contexts. Biphasic current stimulation yielding voltage transients well below the charge injection limit as well as the gel's non-cytotoxicity further underscore its potential for safe and effective neural interfacing applications.
软性生物电子神经接口作为机械上有利的植入式金属电极替代品具有巨大的潜力。在这一追求中，导电水凝胶（CHs）特别可行，将组织顺应性与所需的电化学特性结合在一起。通过将其轻易地合成到可注射系统中，物理聚集的 CHs 提供了另一个优势，从而可以实现微创植入，尽管它们可能由于缺乏对其颗粒大小和堆积的控制而受到阻碍。受这些原理的指导，本文提出了一种可注射的 PEDOT：PSS/基于乙酸的水凝胶，其机械和电化学性能可以通过改变相对乙酸组成来独立调节。该制造工艺进一步受益于采用批量乳液来减小颗粒尺寸并促进更紧密的堆积。所得材料在组织模型和 中注射后既稳定又解剖紧凑，同时在两种情况下都保持有利的电化学性能。双相电流刺激产生的电压瞬变远低于电荷注入极限以及该凝胶的非细胞毒性进一步强调了其在安全有效的神经接口应用中的潜力。
