Dr Robert Langer, winner of the 2015 Queen Elizabeth Prize for Engineering, has made headlines again this week with his latest in potentially life-changing drug therapies.

Hidden within the innermost section of your ear are thousands of tiny hair cells, detecting sound waves and transforming them into signals to send to our brains. These hair cells allow us to hear our favourite music, chat to our friends and listen out for the doorbell. Yet damage to these delicate cells is the leading cause of hearing loss, meaning more than 360 million people around the world miss out on these sounds.  

Each of us is born with around 15,000 hair cells in each ear; but once they’re gone, they’re gone. Cells can be damaged and killed by loud noises, antibiotics or chemotherapy drugs, or even just getting older. Some animals, such as birds and amphibians can regenerate damaged cells, but for mammals (including us) there’s no such luck.

However, with the help of Dr Langer and his expert team, things could all be about to change. Researchers at MIT, Brigham and Women’s Hospital and Massachusetts Eye and Ear have discovered a combination of drugs to regrow hair cells which could return hearing.

Speaking to MIT, Langer said: “Hearing loss is a real problem as people get older. It’s very much of an unmet need, and this is an entirely new approach.” Joining him as senior authors on the study were Langer’s former student Jeffrey Karp, a bioengineer at Brigham and Women’s Hospital (BWH) in Boston; and Albert Edge, a professor of otolaryngology at Harvard Medical School, based at Massachusetts Eye and Ear.

Gut feeling

The idea for Dr Langer’s latest project came from a previous study, looking at a different part of the body. In 2013, Karp, Langer and Xiaolei Yin, another researcher on the team, were looking at young cells from the intestines. When they exposed these cells to different drugs, they could trigger them to change from one cell type to another.

The researchers also discovered that structural cells from the inner ear contain the same proteins as the intestinal cells. Using the same method as in their previous study, the team added a chemical to the inner ear cells that made them multiply quickly. Once they had a large enough group of cells, they added in a second chemical, triggering them to change into mature hair cells.

This new approach has already proved around 60 times more efficient than previous methods of creating new hair cells. Even better, because the treatment involves simply exposing cells to the drug, it should be easy to administer to patients. The idea is that the drug can be injected into the middle ear of a patient, in the same way as drugs are delivered to treat ear infections. Once in the middle ear, the drug would travel across a membrane into the inner ear where it is required.

Treating from 2018

A company called Frequency Therapeutics, started by several of the key researchers, have licensed the technology and plan to begin treating trial patients within 18 months. The team also hope that their work will serve as a useful tool for other researchers, driving study into new solutions to treat hearing loss.

Looking towards their next project, Langer, Karp and Yin are already working on applying their approach to different types of cells. One idea could see them triggering intestinal cells to produce and regulate insulin, providing new therapies for people with diabetes.

Dr Langer was awarded the 2015 Queen Elizabeth Prize for Engineering for his pioneering work in large-molecule drug delivery systems. His research, which has provided treatments for cancers, diabetes and mental illnesses, has touched the lives of more than 2 billion people worldwide.