Local Drug Delivery to Inner Ear for Treatment of Hearing Loss

Sensorineural hearing loss (SNHL) is one of the most common disabilities in our society. Experimentally, many candidates for use as therapeutic molecules have been discovered. However, a considerable obstacle to clinical application is the lack of an effective method for drug delivery to the cochlea. In order to overcome this obstacle, there needs to be development of a local cochlear drug delivery system. Advances in pharmacological technology have provided various drug delivery systems that use biomaterials, and which can be utilized for local drug delivery to the cochlea. Indeed, recent studies have demonstrated the potential of synthetic and natural biomaterials for local drug delivery to the cochlea, indicating that the clinical application of such local drug delivery systems could be used in the near future for therapeutic treatments. Recent progress in cell therapy research also offers a novel drug delivery method for the cochlea. In addition, transplantation of stem cells into the cochlea has been demonstrated to provide protective effects for the auditory function. Transplantation of genetically engineered cells has also resulted in the sustained delivery of aimed therapeutic molecules within the inner ear. Although problems involving clinical application still need to be resolved, these drug delivery systems for the inner ear may hold the future therapeutic options for treatment of SNHL.