Modifizierte Edelmetalloberflächen für neuronale Elektroden

authored by

Kim Dana Kreisköther

supervised by

Peter Behrens

Abstract

Deafness not only means the loss of a sensory organ, it also leads to social isolation in many cases. The number of people with hearing loss is increasing every year, which is why the development of hearing aids is playing a growing role in society. One method to regain auditory perception is the insertion of a cochlear implant, which, however, does not restore the optimal biological state. Therefore, the first part of the present work is devoted to the establishment of an implant-associated drug delivery system, and the second part of the work investigates approaches to biochemical modification to improve electrode-nerve interaction. The contacts of neuronal electrodes are usually made of dense platinum due to its chemical inertness, excellent conductivity, and good biocompatibility. To achieve drug delivery from the platinum contacts, they are coated with a nanoporous platinum coating and characterized in the present work. Pores with different diameters can be used as reservoirs for active agents of varying size. The combination of an electrochemical deposition process and a template-based synthesis intends to exploit the advantages of a controlled coating method for the generation of pores. By variation of the thickness of the nanoporous coating as well as by chemical modification, an adjustable drug delivery system is generated. Release experiments show that chemical modification has no influence on the release behaviour. By varying the coating thickness, an adjustable delivery system is obtained from the nanoporous platinum coating. The electrochemical properties can be improved by coating with nanoporous platinum, which is attributed to the increased specific surface area. Cell culture investigations show good cytocompatibility. Finally, real electrode contacts of a cochlear implant are coated with the developed nanoporous platinum coating to demonstrate the transferability of the developed coating to applications. In a second approach, the modification of precious metal surfaces with the neuronal adhesion molecule L1CAM is investigated to improve electrode-nerve interaction. Qualitative statements about the amount of the immunologically active L1CAM attached can be made using an enzyme-linked immunosorbent assay. To evaluate the results, this is performed on the one hand directly on the substrate surface, and on the other hand the concentration is determined indirectly by electrochemical L1CAM detachment.

Organisation(s)

Inorganic Solid State and Materials Chemistry group

Type

Doctoral thesis

No. of pages

233

Publication date

2021

Publication status

Published

Sustainable Development Goals

SDG 3 - Good Health and Well-being

Electronic version(s)

https://doi.org/10.15488/11548 (Access: Open)