Fibranz Lennart, Behrends Wiebke, Wulf Katharina, Raggl Stefan, Kötter Lisa, Eickner Thomas, Schilp Soeren, Lenarz Thomas, Paasche Gerrit
Department of Otorhinolaryngology, Hannover Medical School, 30625 Hannover, Germany.
Lower Saxony Center for Biomedical Engineering, Implant Research and Development (NIFE), Hannover Medical School, 30625 Hannover, Germany.
J Funct Biomater. 2025 Jan 18;16(1):33. doi: 10.3390/jfb16010033.
Cochlear implants are well established devices for treating severe hearing loss. However, due to the trauma caused by the insertion of the electrode and the subsequent formation of connective tissue, their clinical effectiveness varies. The aim of the current study was to achieve a long-term reduction in connective tissue growth and impedance by combining surface patterns on the electrode array with a poly-L-lactide coating containing 20% diclofenac. Three groups of six guinea pigs each (control, structure, structure with diclofenac in the coating) were implanted for four weeks. The hearing thresholds were measured before implantation and after 28 days, and impedances were monitored over time. After histological preparation, connective tissue growth and spiral ganglion neuron (SGN) survival were quantified. The hearing thresholds and impedances increased over time in all groups, showing no significant differences. The treatment groups showed increased damage in the cochlea, which appeared to be caused by the elevated parts of the microstructures. This seems to be amplified by the trauma model used in the current study. The impedances correlated with connective tissue growth near the electrode contacts. In addition, SGN survival was negatively correlated with the presence of connective tissue, both of which highlight the importance of successfully reducing connective tissue formation after cochlear implantation.
人工耳蜗是治疗重度听力损失的成熟设备。然而，由于电极插入造成的创伤以及随后结缔组织的形成，其临床效果存在差异。本研究的目的是通过将电极阵列上的表面图案与含有20%双氯芬酸的聚-L-丙交酯涂层相结合，实现结缔组织生长和阻抗的长期降低。将三组豚鼠，每组六只（对照组、结构组、涂层中含双氯芬酸的结构组）植入四周。在植入前和28天后测量听力阈值，并随时间监测阻抗。经过组织学制备后，对结缔组织生长和螺旋神经节神经元（SGN）存活情况进行量化。所有组的听力阈值和阻抗均随时间增加，无显著差异。治疗组在耳蜗中显示出更多损伤，这似乎是由微结构的凸起部分引起的。在本研究使用的创伤模型中，这种情况似乎被放大了。阻抗与电极触点附近的结缔组织生长相关。此外，SGN存活与结缔组织的存在呈负相关，这两者都凸显了成功减少人工耳蜗植入后结缔组织形成的重要性。
