Stem-cell therapy for hearing loss: are we there yet?

Area of Science:

• Regenerative Medicine
• Otolaryngology
• Neuroscience

Background:

• Mammalian hair cells and auditory neurons lack regenerative capacity, leading to permanent hearing loss.
• Current treatments cannot fully restore auditory function after damage to these cells.
• Stem cell therapy offers a potential alternative for regenerative treatment.

Purpose of the Study:

• Review stem cell types for sensorineural hearing loss therapy.
• Summarize key animal experiments in stem cell therapy for hearing loss.
• Highlight recent advancements in the field of auditory regenerative medicine.

Main Methods:

• Comprehensive literature search across PubMed/MEDLINE, Web of Science, Science Direct, and SciELO.
• Inclusion of gray literature in the research.
• Keywords included "stem cells," "hair cells," "auditory neurons," "mesenchymal," "iPS," "inner ear," and "auditory."

Main Results:

• High success rates observed in differentiating stem cells into hair cells (up to 82%) and auditory neurons (100%).
• Differentiated stem cells formed new synapses with cochlear explants.
• Auditory restoration after transplantation was documented only in deafferented animal models.

Conclusions:

• Stem cell therapy advancements are most significant for auditory neuropathy.
• Cell-based therapies may improve outcomes for cochlear implant recipients.
• Further research is needed to translate these findings into clinical applications for broader hearing loss.