3D Bioprinting Inner Ear Organ of Corti Organoids Induce Hair Cell Regeneration.

Hearing loss is often regarded as "invisible disability" which seriously affects the quality of life. The majority of hearing loss cases are caused by the damage to inner ear hair cells or connected spiral ganglion cells, and there is a lack of effective treatment measures. In recent years, significant progress has been made in the use of two-dimensional (2D) culture systems to induce the regeneration of auditory cells. However, the regenerated hair cells cannot form effective functional ciliary bundles under the 2D system, let alone establish synaptic contact with spiral ganglion cells, so they cannot truly achieve physiological repair of hearing. In this study, our aim is to construct a three-dimensional (3D) organ of Corti organoid through 3D bioprinting, which combines "3D culture scaffold + multiple induction signals + inner ear stem cells." Then we evaluate the effects of the organoids on the differentiation of inner ear stem cells into auditory cells. We found that the organoids promoted adhesion and growth of inner ear stem cells, as well as the production of hair cells and nerve cells. The research may develop a novel approach for studying auditory cell regeneration and hearing loss repair.