Stem Cells Injected Into the Deaf Rat Cochlea via Round Window Could Survive for at Least 1 Week in the Endolymph

Background and Aim: Noise-Induced Hearing Loss (NIHL) occurs dueto prolonged exposure to high-intensity sound. Although NIHL has beenwidely studied over the past decades, hearing aids and cochlear implantare only clinically effective in the treatment of hearing loss. In recentyears, stem cell transplantation has been investigated to repair damagedtissues of the inner ear (hair cells and auditory neurons). Because of smallsize and the complex structure of the cochlea, stem cell implantationis difficult. It is necessary, stem cell injection procedure has a minimaladverse effect on the target tissue. Cochleostomy was currently used forstem cell injection which can damage to the hearing. In addition, the cellsurvival rate is an essential factor for damaged hair cells regeneration.Therefore, we investigated the survival rate of injected bone marrowderivedmesenchymal stem cells (BMSCs) through a round window in arat model of NIHL.Methods: For the hearing loss induction, adult male rats were subjectedto white noise (110 dB) paradigm for 6 hours in 5 days. Distortionproductotoacoustic emission (DPOAE) were recorded before and afternoise exposure. Hoechst labeled - MSCs were implanted into the ratcochlea via the round window. Number of Hoechst- labeled cells wereassayed in the endolymph for 24 h, 72 h, 7 and 10 days after injection.Results: Our data show that stem cell transplantation into the cochlea through round window niche is a safe surgical approach. As well,implanted cells survived in the endolymph for a postoperative period ofat least 1 week.Conclusion: BMSCs can survive in the adult rat cochlea for at least 1week after injection through the round window niche.

کلیدواژه ها:

BMSCs ، Round Window ، Survival Rate ، Endolymph