Local drug delivery systems for the inner ear

Abstract Objectives Recent advancements in molecular biology have led to a better understanding of the mechanisms associated with sensorineural hearing loss and other inner ear diseases. These developments offer hope for new treatment approaches benefiting millions of patients. However, drug therapy for the cochlea presents significant challenges, necessitating the development of innovative technologies to ensure safe and effective delivery of therapeutic compounds. Among these emerging technologies, microfluidic-based delivery systems are gaining attention as a promising method for direct intracochlear administration. Ultimately, these systems have the potential to provide sustained release of regenerative compounds, thereby restoring hearing in patients suffering from various auditory conditions. Key findings This article provides a comprehensive review of recent progress in the field of intracochlear drug delivery systems. In addition, the review encompasses passive systems, such as osmotic pumps, as well as active microfluidic devices. Moreover, the article discusses the integration of these delivery systems with existing cochlear implants. The primary objective is to offer a concise overview of the current state of development for intracochlear drug delivery systems, which can be combined with emerging therapeutic compounds to effectively treat inner ear diseases. Conclusions The safe and effective treatment of auditory diseases requires the development of microscale delivery devices capable of extended operation and direct application to the inner ear. To achieve this, significant advancements in miniaturization and integration of multiple functions are necessary. These functions include drug storage, delivery, power management, and sensing, ultimately enabling closed-loop control and timed-sequence delivery devices for the treatment of these diseases.