Biohybrid cochlear implants: neural interfaces, regenerative pathways, and translational benchmarks

Cochlear implants (CIs) restore hearing by electrically stimulating the auditory nerve, yet the millimeter-scale electrode-neuron separation limits spatial selectivity and temporal fidelity. Rather than relocating the electrode array, we propose a biohybrid strategy that preserves the conventional scala tympani insertion and closes this gap biologically by interposing living neural constructs between the array and the modiolus. This approach leverages the Canaliculi Perforantes of Schuknecht (CPS) to deliver spatially confined biochemical, mechanical, and electrical cues from the scala tympani, biasing spiral ganglion neurites toward contacts while respecting surgical practicality. We review CPS microanatomy and transport, auditory neuron/stem cell-regeneration prospects, hydrogel/assembloid niches, surface and material stacks, and conclude with translational benchmarks, constraints, and a near-mid-long-term roadmap.