Magnetic nanoparticles could revolutionize the delivery of drugs for hearing loss

Just as a company needs an effective and reliable service to deliver its goods to customers, medications need an effective delivery system to get them to the specific areas of the body where they can have their effect.

Daniel Sun, MD, of the University of Cincinnati has received a career development grant of just over $1 million from the National Institute on Deafness and Other Communication Disorders of the National Institutes of Health to explore the potential of using magnetic nanoparticles as a delivery system for drugs to reach the inner ear to treat hearing loss.

Aside from steroids, which are often ineffective, there are currently no FDA-approved drugs to treat hearing loss. And getting the drugs to the inner ear, where the hearing loss occurs, is a major hurdle.

“There are a lot of interesting drugs in development that have the potential to change the way hearing loss is treated and allow us to delay or even reverse hearing loss,” said Sun, who is the Myles L. Pensak, MD, endowed professor of neurotology and skull base surgery, director of the division of neurotology, director of the neurotology fellowship program and associate professor of otolaryngology at the University of Cincinnati College of Medicine and a UC Health physician. “But we don't have a good way to really effectively get these promising drugs into the ear.”

Magnetic nanoparticles are already used in other parts of the body as drug delivery systems, but Sun said his research contributes to a better understanding of how to design the nanoparticles specifically for the anatomy of the ear.

The goal is to create something that is minimally invasive and then use a magnetic field to direct these nanoparticles into the ear where the hearing loss occurs.”

Daniel Sun, MD, University of Cincinnati

Different types of hearing loss, such as age-related hearing loss, noise trauma and sudden hearing loss, are caused by different mechanisms and are therefore treated with different medications. If magnetic nanoparticles are effective, they could act as a delivery truck, loading the specific medications each patient needs depending on the type of hearing loss they have.

“Because of their design, these particles can carry many different types of drugs,” Sun said. “It's important that we can use a common platform for different drugs targeting different types of hearing loss.”

In addition to magnetic field research, Sun and Dr. Donglu Shi of UC's School of Mechanical and Materials Engineering are jointly studying the effectiveness of lasers in activating the nanoparticles and allowing them to penetrate the inner ear.

“We want to be very systematic and thorough to really understand how we can design these nanoparticles to be biocompatible and safe for hearing and balance function in the ear,” Sun said. “At the same time, we want to provide very robust drug delivery options. We're really starting from the ground up to understand how these particles penetrate the membrane that separates our middle ear from the inner ear, and how these particles actually get into the areas of the inner ear that we want them to go into.”

In the long term, Sun said, a breakthrough in drug delivery combined with the development of new drugs could open up a new world of noninvasive treatment for hearing loss.
“We really want to look to a future where people, regardless of age or health status, can safely undergo these treatments with these promising drugs in a way that is minimally invasive while effectively treating their hearing loss,” he said.

Sun initially received this scholarship while studying at Johns Hopkins University, and it was transferred when he joined the UC faculty.