Regenerative cochlear implants
Sensorineural hearing loss (SNHL) is a degeneration of the sensory cells or primary auditory neurons (ANs) present in the inner part of the ear called the cochlea. CIs effectively restore hearing, but their utility could be improved by blocking further neural degeneration and restoring synaptic connections for better speech discrimination, especially in noisy environments. The NEUEAR (Neurotrophic cochlear implant for severe hearing loss) project designed encapsulated cell (EC) technology that can be used with or without the CI to deliver neurotrophic factors and prevent further AN degeneration. The devices were tested on two animal models of hearing loss to determine the feasibility of this approach and facilitate the commercialisation of promising results. Researchers produced and characterised cell clones for the EC device. In vitro testing revealed that the brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor clones provided the best neuroprotection. NEUEAR successfully developed CI and EC device prototypes for cochlear co-implantation in cats and guinea pigs. The intracochlear delivery of neurotrophic factor from EC devices showed neuroprotective effects in the guinea pig model. The NEUEAR team designed functional prototypes of neurotrophic EC and CI devices for co-implantation or separate implantation. However, they settled on the separate EC implantation model for future human clinical trials as it is more flexible and does not require CI modification. Researchers then developed and successfully tested their extension of perilymphatic space implantation port concept in human temporal bone. Research outcomes have been widely disseminated to key stakeholders, including patients' associations and charities, the scientific community and the European Commission. NEUEAR's innovative EC and CI designs are currently being patented and are slated for testing in a clinical phase I trial that was due to commence after the project ended. These prototypes could significantly enhance the hearing experience of SNHL patients. Successful commercialisation of EC and CI prototypes should increase the competitiveness of the project’s industrial partners in a global CI market worth billions of dollars. Furthermore, the EC prototype alone could be adapted for other regenerative therapies.
Keywords
Regenerative, cochlear implants, severe hearing loss, NEUEAR, neurotrophic, encapsulated cell