For many people, a hearing loss diagnosis can seem pretty daunting. While many kinds of hearing loss can, indeed, be treated, there are quite a few for which there is currently no definitive treatment or cure. People who are diagnosed with irreversible hearing loss can often feel some anxiety, stress or sadness over their hearing loss and how it will affect their life moving forward.
Although many forms of hearing loss are still, to this day, incurable, new research from scientists at USC, the University of Tübingen, and Harvard suggests that there may be a new approach to repairing cells located deep inside the ear. Such procedures could hold the key to restoring the hearing abilities of millions of people who suffer from certain forms of hearing loss.
This study looked at a new way for a drug to hone in on the damaged nerves and cells inside the ears of people with hearing loss. Such an approach could potentially remedy the damage to cells that occurs with age or through traumatically loud noises.
To make this drug work, however, the scientists had to overcome a major obstacle: they needed to design a way to deliver a particular drug into the inner ear and make it stay in the same place long enough to do its job. Seems simple, right?
It turns out that the inner ear is full of fluid that’s constantly flowing around. While this fluid does an important job (it’s one of the many things responsible for our sense of balance) it does make the life of any medication in the inner ear quite difficult. This fluid generally sweeps away and dissolves drugs, thereby rendering them useless.
To solve this issue, the researchers needed to develop a totally new method to deliver the drug into the inner ear. To do so, the researchers actually targeted the choclea, which uses a plethora of hair-like sensitive cells to send sound messages to the brain. Over time, the hair-like sensory cells in the ear break down and age, which distorts or disrupts the hearing and understanding processes.
The researchers then designed a new molecule by combining 7,8 dihydroxyflavone, which can act like a protein required for the proper development and function of the nervous system, with the substance biphosphate, which is great at sticking to bones. The combination of these two substances allows 7,8 dihydroxyflavone to do its job while biphosphate keeps it in place and prevents it from getting swept away by the fluid of the inner ear.
During the study, the researchers found that neurons responded well to the molecule by regenerating synapses within mice ear tissue. This ultimately led to the repair of the sensitive hair cells and neurons necessary for proper hearing.
While the drug has yet to be tested on living animals or humans, it does give many in the scientific community hope that we may have a treatment or cure for hearing loss sometime in the future. Such breakthroughs are critical for our understanding of hearing loss development and may be key in one day treating the millions of people who suffer from hearing loss each year.