SCIENTISTS: WE ARE A STEP CLOSER TO CURING DEAFNESS

A SIMPLE jab could one day cure hearing loss, according to a study.

Scientists have discovered a drug combination they believe could be injected into the inner ear to regenerate the hair cells that enable us to process sounds.

Hairs detect sound waves within the inner ear and translate them into nerve signals that allow us to hear speech, music and everyday noises.

Each of us is born with about 15,000 hair cells per ear but once damaged they are unable to regrow, one of the leading causes of hearing loss.

However, researchers have now discovered a combination of drugs that increases numbers of progenitor cells, also called supporting cells, in the ear and induces them to become hair cells. They believe the process offers a potential new way to treat hearing loss.

Study senior author Professor Robert Langer, of Massachusetts Institute of Technology (MIT) in the US, said: “Hearing loss is a real problem as people get older.

Regenerate

“It’s very much an unmet need and this is an entirely new approach.”

More than 900,000 people in Britain are severely or profoundly deaf.

These include more than 45,000 children, plus many more with temporary hearing loss.

More than 70 per cent of people aged over 70 and 40 per cent of those over 50 have some kind of hearing loss.

Noise exposure, ageing and some antibiotics and chemotherapy drugs can lead to hair cell death in the ear.

In some animals the cells naturally regenerate – but not in humans.

The research team began investigating the possibility of regenerating hair cells during an earlier study on cells of the intestinal lining.

The team became aware that cells which provide structural support in the inner ear express some of the same surface proteins as intestinal stem cells.

The researchers decided to explore whether the same approach would work in those supporting cells.

They found that their new approach also worked in a mouse ear removed from the body.

As the new treatment involves a simple drug exposure, the researchers believe it could be easy to administer it to human patients.

They envisage that the drugs could be injected into the middle ear, from where they would diffuse across a membrane into the inner ear.

This type of injection is commonly used to treat ear infections.

Some of the researchers have started a company called Frequency Therapeutics, which has licensed the technology and plans to begin testing it on human patients within 18 months.

Lead author Doctor Will McLean, a recent PhD recipient at the Harvard-MIT Division of Health Sciences and Technology, said: “We hope that our work will allow other scientists to pursue studies of supporting cells and hair cells that have not been possible because such limited quantities of hair cells were available.”

Innovative

Senior author Doctor Jeffrey Karp, an associate professor of medicine at Brigham and Women’s Hospital, in Boston, added: “Researchers who have been eager to conduct experiments on inner ear hair cells will now be able to replicate our work and have huge numbers of them to do all kinds of experiments.”

The team is also working on applying the innovative approach to other types of cells, including types of intestinal cells involved in insulin regulation.

The findings, published in the journal Cell Reports, received a cautious welcome from the British Deaf Association last night.

A spokesman said not all profoundly deaf people would want to be able to hear. He said: “Many of our beneficiaries consider that having a deaf identity is a positive aspect of being human and is part of the rich tapestry of life.”