Growing human-scale scala tympani-like<i>in vitro</i>cell constructs.

Abstract

Emerging materials and electrode technologies have potential to revolutionise development of higher resolution next-generation, bionic devices. However, barriers associated with the extended timescales, regulatory constraints, and opportunity costs of preclinical and clinical studies, can inhibit such innovation. Development of<i>in vitro</i>models that mimic human tissues would provide an enabling platform to overcome many of these barriers in the product development pathway. This research aimed to develop human-scale tissue engineered cochlea models for high throughput evaluation of cochlear implants on the bench. Novel mould-casting techniques and stereolithography three-dimensional (3D) printing approaches to template hydrogels into spiral-shaped structures resembling the scala tympani were compared. While hydrogels are typically exploited to support 3D tissue-like structures, the challenge lies in developing irregular morphologies like the scala tympani, in which the cochlear electrodes are commonly implanted. This study successfully developed human-scale scala tympani-like hydrogel structures that support viable cell adhesion and can accommodate cochlear implants for future device testing.