Inner ear therapy for neural preservation.
A gradual loss of auditory neurons often occurs following sensorineural hearing loss. Since the cochlear implant must stimulate the remaining auditory neuron population, it would be beneficial to preserve as many auditory neurons as possible. Neurotrophic factors protect auditory neurons from degradation after sensorineural hearing loss in experimental animals, but have not yet been translated into the clinical setting. Current experimental and clinical techniques for drug delivery to the inner ear are examined in this review, covering the routes for drug delivery to the cochlea and the delivery systems used to introduce them. Duration of treatment, drug diffusion, effectiveness and safety are discussed with references to how they may be translated to the implementation of neurotrophic factor treatment for neural preservation.
Richardson
Rachael T
RT
The Bionic Ear Institute, East Melbourne, Victoria 3002, Australia. rrichardson@bionicear.org
Noushi
Farnoush
F
O'Leary
Stephen
S
D000818:Animals; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D007758:Ear, Inner / Q000378:metabolism / Q000473:pathology; D015316:Genetic Therapy; D006168:Guinea Pigs; D006198:Hair Cells, Auditory / Q000378:metabolism / Q000473:pathology; D006319:Hearing Loss, Sensorineural / Q000473:pathology* / Q000517:prevention & control; D006801:Humans; D007260:Infusion Pumps; D007759:Labyrinth Diseases / Q000188:drug therapy* / Q000628:therapy; D009414:Nerve Growth Factors / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*; D009474:Neurons / Q000187:drug effects*; D010539:Permeability; D012405:Round Window, Ear / Q000378:metabolism; D012533:Scala Tympani / Q000378:metabolism; D013136:Spiral Ganglion / Q000166:cytology / Q000187:drug effects; D033581:Stem Cell Transplantation; D014722:Vestibule, Labyrinth / Q000378:metabolism
D003692:Delayed-Action Preparations; D009414:Nerve Growth Factors