Nguyen Diep, Valet Manon, Dégardin Julie, Boucherit Leyna, Illa Xavi, de la Cruz Jose, Del Corro Elena, Bousquet Jessica, Garrido Jose A, Hébert Clément, Picaud Serge
INSERM, CNRS, Institut de la Vision, Sorbonne Université, Paris, France.
Instituto de Microelectrónica de Barcelona, IMB-CNM (CSIC), Bellaterra, Spain.
Front Neurosci. 2021 Mar 4;15:615256. doi: 10.3389/fnins.2021.615256. eCollection 2021.
Evaluating biocompatibility is a core essential step to introducing a new material as a candidate for brain-machine interfaces. Foreign body reactions often result in glial scars that can impede the performance of the interface. Having a high conductivity and large electrochemical window, graphene is a candidate material for electrical stimulation with retinal prosthesis. In this study, non-functional devices consisting of chemical vapor deposition (CVD) graphene embedded onto polyimide/SU-8 substrates were fabricated for a biocompatibility study. The devices were implanted beneath the retina of blind P23H rats. Implants were monitored by optical coherence tomography (OCT) and eye fundus which indicated a high stability up to 3 months before histology studies were done. Microglial reconstruction through confocal imaging illustrates that the presence of graphene on polyimide reduced the number of microglial cells in the retina compared to polyimide alone, thereby indicating a high biocompatibility. This study highlights an interesting approach to assess material biocompatibility in a tissue model of central nervous system, the retina, which is easily accessed optically and surgically.
评估生物相容性是将一种新材料引入脑机接口候选材料的核心必要步骤。异物反应通常会导致胶质瘢痕，从而阻碍接口的性能。石墨烯具有高导电性和大的电化学窗口，是用于视网膜假体电刺激的候选材料。在本研究中，制备了由嵌入聚酰亚胺/SU-8基板的化学气相沉积（CVD）石墨烯组成的非功能性器件，用于生物相容性研究。将这些器件植入盲P23H大鼠的视网膜下方。通过光学相干断层扫描（OCT）和眼底对植入物进行监测，结果表明在进行组织学研究之前，植入物在长达3个月的时间内具有很高的稳定性。通过共聚焦成像进行的小胶质细胞重建表明，与单独的聚酰亚胺相比，聚酰亚胺上存在石墨烯减少了视网膜中小胶质细胞的数量，从而表明其具有高生物相容性。本研究突出了一种在中枢神经系统组织模型视网膜中评估材料生物相容性的有趣方法，视网膜在光学和手术方面都易于触及。
