Drug delivery in cochlear implantation

Abstract

Intra-cochlear fibrous tissue formation around the electrode following cochlear implantation affects the electrode impedance as well as electrode explantation during reimplantation surgeries. Applying corticosteroids in cochlear implantation is one way of minimizing the intra-cochlear fibrous tissue formation around the electrode. It were J. Kiefer, C. von Ilberg, and W. Gstöttner who proposed the first idea on drug delivery application in cochlear implantation to MED-EL in the year 2000. During the twenty years of translational research efforts at MED-EL in collaboration with several clinics and research institutions from across the world, preclinical safety and efficacy of corticosteroids were performed leading to the final formulation of the electrode design. In parallel to the drug eluting CI electrode development, MED-EL also invested research efforts into developing tools enabling delivery of pharmaceutical agents of surgeon’s choice inside the cochlea. The inner ear catheter designed to administer drug substances into the cochlea was CE marked in 2020. A feasibility study in human subjects with MED-EL CI featuring dexamethasone-eluting electrode array started in June 2020. This article covers the milestones of translational research towards the drug delivery in CI application that took place in association with MED-EL.

Graphical Abstract

Chinese abstract

人工耳蜗植入后, 电极周围的人工耳蜗内纤维组织的形成会影响再植入手术期间的电极阻抗以及电极外植。在耳蜗植入中施用皮质类固醇是使电极周围耳蜗内纤维组织形成最小化的一种方法。2000年Kiefer教授,、von Ilberg教授 和Gstöttner教授首次向MED-EL提出了在耳蜗植入时应用药物输入的想法。花了20年的时间开发的药物洗脱电极, 于2020年将首次植入人类。本章将向您展现, MED-EL与世界各地的多家诊所合作进行的20年转化研究。在这二十年中, 大部分时间都花在确定药物剂量以及评估皮质类固醇对非人类受试者的安全性和有效性上。在开发药物洗脱CI电极的同时, MED-EL还进行了研究工作, 开发了药物输入工具, 将外科医生选择的任何药物输入至耳蜗内。

Keywords:

• Fibrous tissue
• electrode impedance
• drug eluting electrode
• pharmacokinetic
• cochlear catheter

Acknowledgments

The authors would gratefully like to acknowledge the key contributors to the development of the subject matter. Their contributions are outlined in this article. The authors further acknowledge Carolyn Garnham and Soeren Schilp from MED-EL for their valuable input and comments during several rounds of review meetings that contributed to the final version of this article.

Disclosure statement

This article is sponsored by MED-EL and has not undergone the regular peer-review process of Acta Oto-Laryngologica. Both the authors are affiliated with MED-EL.