Nasal spray could ‘wash’ brain clean of Alzheimer’s disease proteins

A nasal spray that helps ‘wash’ Alzheimer’s-causing proteins out of the brain could one day offer hope to millions who suffer from the disease.

Alzheimer’s is the most common form of dementia, affecting more than 940,000 people in the UK alone. As the world’s population ages, the number is increasing, expected to almost double every 20 years.

While the causes of the disease are still not fully understood, scientists have been studying the build-up of tau proteins in the brain that lead to cognitive decline. The proteins clump and form tangles, disrupting signals along neurons, or brain cells.

Now, a team from the University of Texas Medical Branch (UTMB) has found a potential way to get rid of the proteins.

The team developed a specific type of antibody, called TTCM2, which targets and clears tau plaques, or build-ups, restoring brain function. 

To deliver the antibody straight to the brain, they hid it inside tiny particles that can be delivered by a nasal spray.

Traditionally, drugs are delivered to the brain in the bloodstream, but this means they must be able to cross the tricky blood-brain barrier. 

However, there is a more direct, non-invasive route, in which drugs can pass directly from the nasal mucosa – the sensitive lining of the nasal cavity – to the brain, known as intranasal administration.

The UTMB team tested this route on mice with tau build-ups similar to humans, and found it cleared the plaques after just one spray, resulting in significant cognitive improvements. In addition, it also resulted in higher levels of proteins that are beneficial for brain cell communication.

Lead author Dr Rakez Kayed said: ‘This nasal spray approach opens new avenues for non-invasive delivery of tau therapeutic antibodies directly to the brain, and it holds promise for many neurodegenerative diseases.

‘This method not only improves the delivery of therapeutic antibodies but also enhances their efficacy in clearing tau aggregates and improving cognitive functions.’

However, while the results are very exciting, the nasal spray antibody has so far only been tested in mice – more research is needed to determine if the treatment would be safe and effective in humans. The UTMB team plans to conduct further preclinical trials, with the aim of moving on to human testing.

First author Sagar Gaikwad said: ‘This advancement could significantly impact the treatment strategies for Alzheimer’s and related tauopathies, offering new hope for millions of patients suffering from these debilitating conditions.’