BACKGROUND:  Direct inner ear drug delivery holds the promise for improved treatment of auditory and vestibular dysfunction, such as Meniere's disease. At the same time, a safe and feasible approach that enables the delivery of controllable doses into the inner ear fluids and minimizes the risk of adverse effects on inner ear neural structures is highly desirable in clinical applications. There have been a few attempts to develop inner ear delivery methods in animal models, which could be used as 1) platforms for developing therapeutic approaches in humans and 2) experimental models for subclinical studies of pharmacokinetics and ototoxic effects of therapeutic agents. However, none of the current methods in animal models provides both the ability to control the dosage and duration of the delivery, and demonstrates minimal risk and also free of long-term effects.

INNOVATION:  Researchers at UCLA have developed an animal model by surgically implanting a small port inside an ear of a chinchilla, a rodent widely used in inner ear research. The device allows direct access to the perilymphatic fluid compartment of the inner ear surrounding cochlear and vestibular tissues. Therapeutic agents can then be precisely administrated into the inner ear at controllable dosages and durations. In the meantime, this device enables the sampling of the inner ear fluids. Potentially, this device could also be used for gene delivery, cell delivery, imaging and installation of electrical prosthetic in the inner ear. The animal model could also be used as a platform to develop similar devices for humans and other animals.

POTENTIAL APPLICATIONS 

• Subclinical studies of direct inner ear drug delivery.
• Subclinical studies of treatments for inner ear disorders including Meniere's disease and age-related inner ear functional deficits.
• Sampling and bioassay for ototoxic effects of therapies, such as chemotherapeutic agents.
• Research on inner ear pathophysiology and disorders, such as Meniere's disease.

ADVANTAGES

• Direct and precise administration of therapeutic agents into the inner ear.
• Ability to control the dosage and duration of inner ear administration of therapeutic agents.
• Direct access to inner ear perilymph and vestibular and cochlear tissues.
• Surgical site is distal to neural structures, minimizing the risk of trauma.
• No long-term adverse effects.

DEVELOPMENT-TO-DATE:  This animal model is routinely used for in vivo studying inner ear pathophysiology and recovery investigations in the inventors' UCLA laboratory.

Reference: UCLA Case No. 2009-272