Dubai, United Arab Emirates – Hearing aids are a vital lifeline for millions of people around the world, enabling them to stay in constant contact with the world around them, but they do not restore hearing. These devices work by amplifying sounds, and despite their modern and elegant designs, many still suffer from the “stigma” associated with wearing them.
A clinical trial is now underway in Britain, the first of its kind in the world, to test a pioneering new treatment that, if successful, could completely eliminate the need for hearing aids for some people.
The innovative treatment relies on injecting laboratory-grown stem cells into the damaged ear, hoping they will grow into new, healthy auditory neurons that can transmit sounds from the inner ear to the brain, replacing cells irreversibly damaged by aging, defective genes, or infections such as measles or mumps.
It is noteworthy that there is currently no treatment for this type of nerve damage.
Successful animal experiments
In animal tests, the stem cell injection not only proved safe, but also significantly improved hearing.
Following successful animal experiments, the syringe’s developer, Rainery Therapeutics, a startup from the University of Sheffield, was given the green light to trial the treatment on 20 patients with severe hearing loss, to see if the same results are possible in humans.
The company developing the injection hopes that a single dose of a stem cell injection– called “Rincell-1” will completely reverse hearing loss in deaf people due to damage to their auditory nerves.
The clinical trial is expected to be conducted at three NHS sites – University Hospitals Birmingham, University Hospitals Cambridge, and NHS Jays and St Thomas’ – where stem cell treatment under general anesthesia will be provided to 20 severely deaf patients undergoing cochlear implant surgery.
The treatment development team also hopes that it will be possible to inject it without surgery in the future.
The secret of the process
The secret to this process lies in the type of stem cells used. These are called auricular neurons, and they are only one developmental stage away from becoming fully mature auditory neurons. Once they enter the inner ear, these cells jump to final maturity to become fully mature working cells.
“I’ve already decided to become auditory neurons,” says Doug Hartley, chief medical officer at Rainery Therapeutics and professor of otology at the University of Nottingham. We inject it into the small space between the inner ear and the brain, and tests show that it stays in place and, more importantly, does not turn into any other type of cell.
“This is important,” he added. “One of the long-standing concerns about all stem cell treatments for any condition is whether the injected cells can turn into cancer cells, as they have the potential to turn into any type of cell, including, in theory, cancer cells.”
Professor Hartley says the first results are scheduled to appear in 2027, and if all goes well, the treatment could be used on patients with mild to moderate age-related hearing loss who do not require a cochlear implant.
“This is exciting,” says Kevin Munro, professor of hearing at the University of Manchester. Hearing aids and cochlear implants are helpful, but you still experience a lot of background noise, and they’re not always effective. If successful, this technology could bring about a qualitative shift in the lives of thousands of people suffering from hearing loss as a result of nerve damage.
However, Monroe warned that there is currently no easy way to determine whether a person’s deafness is caused by nerve damage or the destruction of hair cells in the cochlea. Repairing nerve damage is not guaranteed to improve hearing.
Professor Nish Mehta, a consultant ear, nose and throat surgeon at University College London Hospitals, agrees that this treatment is “very promising”.
Mehta told Good Health magazine: “Tests conducted on mice showed that the brain after treatment was receiving audio information, while it had not received it before”.
But he warns of risks associated with this, as opening the inner ear for stem cell injections or cochlear implants can destroy remaining healthy hair cells, damaging any remaining “normal” hearing in the patient.
“About a third of people who undergo cochlear implants lose all their remaining hearing,” he says.
