Institute of Scientific and Industrial Research (ISIR), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka, 567-0047, Japan.
Endowed Research Department of Clinical Neuroengineering, Global Center for Medical Engineering and Informatics, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
Adv Healthc Mater. 2019 May;8(10):e1900130. doi: 10.1002/adhm.201900130. Epub 2019 Apr 4.
Neural interfaces enabling light transmittance rely on optogenetics to control and monitor specific neural activity, thereby facilitating deeper understanding of intractable diseases. This study reports the material strategy underlying an optogenetic neural interface comprising stretchable and transparent conductive tracks and capable of demonstrating high biocompatibility after long-term (5-month) implantation. Ag/Au core-shell nanowires contribute toward improving track performance in terms of stretchability (<60% strain), transparency (<83%), and electrical resistance (15 Ω sq ). The neural interface integrated with gel-coated exterior microelectrodes preserves low impedance (1.1-3.2 Ω cm ) in a saline solution over the evaluated 5-month period. Besides the use of efficient conductive materials, surface treatment using antithrombogenic polymer tends to prevent the growth of granulation tissue, thereby facilitating clear monitoring of electrocorticograms (ECoG) in a rodent during chronic implantation. The flexible and transparent neural interface pathologically exhibits noncytotoxicity and low inflammatory response while efficiently recording evoked ECoG in a nonhuman primate via optogenetic stimulation. The proposed highly reliable interface can be employed in multifaceted approaches for translational research based on chronic implants.
能够实现光透过率的神经接口依赖于光遗传学来控制和监测特定的神经活动，从而促进对难治性疾病的深入理解。本研究报告了一种光遗传学神经接口的材料策略，该接口由可拉伸和透明的导电轨道组成，在长期（5 个月）植入后具有很高的生物相容性。Ag/Au 核壳纳米线有助于提高轨道的拉伸性能（<60%应变）、透明度（<83%）和电阻（15 Ω sq ）。与涂有凝胶的外部微电极集成的神经接口在评估的 5 个月期间在盐溶液中保持低阻抗（1.1-3.2 Ω cm ）。除了使用高效的导电材料外，使用抗血栓聚合物进行表面处理有助于防止肉芽组织的生长，从而便于在慢性植入物期间对啮齿动物的皮层电图（ECoG）进行清晰监测。通过光遗传学刺激，柔性透明的神经接口在非人类灵长类动物中病理表现出非细胞毒性和低炎症反应，同时有效地记录诱发的 ECoG。所提出的高可靠性接口可用于基于慢性植入物的转化研究的多方面方法。
