Otoprotection and inner ear regeneration

Sensory hairs cells are the mechanotransducers of the inner ear that are essential for hearing and balance. Death of hair cells (HCs) commonly occurs following acoustic trauma or exposure to ototoxins such as aminoglycosides or cisplatin, and as a consequence of ageing. It has generally been accepted that hearing loss resulting from hair cell damage is irreversible as the human ear is incapable of regenerating or repairing these sensory elements following severe injury. Therapeutic strategies for inner ear repair can be divided into two main categories: 1) protective means, in order to promote cell survival after damage, and 2) regeneration of HCs, once the cells have died. A systematic review of the literature was carried out through Medline searches in English. This showed that the protection of auditory hair cells is an exciting field and that new therapeutic strategies could possibly reach clinical practice soon. In addition, inner ear regeneration with stem cells is a rapidly evolving and exciting field but it could take longer before practical tools will become available.