Biomaterialien bei Cochlea-Implantaten

Zusammenfassung

Cochlea-Implantate (CI) stellen seit fast 25 Jahren den Goldstandard in der Versorgung taub geborener Kinder bzw. postlingual ertaubter Erwachsener dar. Die Cochlea-Implantate sind damit die Erfolgsgeschichte im Bereich der neurobionischen Prothesen. Durch die inzwischen routinemäßige Versorgung von Erwachsenen, aber besonders auch Klein- und Kleinstkindern, bestehen große Anforderungen an die Implantate. Dies gilt besonders im Hinblick auf die Biokompatibilität der an der Oberfläche befindlichen Anteile des CI. Darüber hinaus existieren erhebliche mechanische Herausforderungen an einzelne Bauteile, wie z. B. Flexibilität bzw. Bruchfestigkeit des Elektrodenträgers und der Bruchfestigkeit des Implantatgehäuses gegen äußere Krafteinwirkungen. Durch die unmittelbare Nähe der Implantate zur Mittelohrschleimhaut, wie auch dem Übergang zur Perilymphe der Cochlea, besteht zumindest die prinzipielle Gefahr eines Übertritts von Bakterien entlang des Elektrodenträgers in die Cochlea. Durch die vielfältigen, an das Cochlea-Implantat gestellten Anforderungen auf dem Gebiet der Biokompatibilität und der Elektrodenmechanik ergibt sich trotz des derzeit bereits hohen technischen Niveaus der Implantate weiterer Spielraum zur kontinuierlichen Verbesserung der Implantat- bzw. Materialeigenschaften und hierdurch gesteigerte Effektivität der Cochlea-Implantate. Nachfolgend soll daher auf grundlegende Materialaspekte der Cochlea-Implantate sowie zukünftige Entwicklungsmöglichkeiten eingegangen werden..

Abstract

Cochlear implants (CI) represent the „gold standard” for the treatment of congenitally deaf children and postlingually deafened adults. Thus, cochlear implantation is a success story of new bionic prosthesis development. Owing to routine application of cochlear implants in adults but also in very young children (below the age of one), high demands are placed on the implants. This is especially true for biocompatibility aspects of surface materials of implant parts which are in contact with the human body. In addition, there are various mechanical requirements which certain components of the implants must fulfil, such as flexibility of the electrode array and mechanical resistance of the implant housing. Due to the close contact of the implant to the middle ear mucosa and because the electrode array is positioned in the perilymphatic space via cochleostomy, there is a potential risk of bacterial transferral along the electrode array into the cochlea. Various requirements that have to be fulfilled by cochlear implants, such as biocompatibility, electrode micromechanics, and although a very high level of technical standards has been carried out there is still demand for the improvement of implants as well as of the materials used for manufacturing, ultimately leading to increased implant performance. General considerations of material aspects related to cochlear implants as well as potential future perspectives of implant development will be discussed.

Schlüsselwörter

Cochlea-Implantat - Biomaterialien - Biokompatibilität - Elektrode - Innenohr - Cochleostomie - Oberflächenfunktionalisierung - Drug Delivery - Nanopartikel - Coating

Key words

cochlear implants - biomaterials - biocompatibility - electrode - inner ear - cochleostomy - surface functionalisation - drug delivery - nanoparticle - coating

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