Leeds research into ‘microbubble’ drug delivery could revolutionise fight against cancer

Professor Stephen Evans.
Professor Stephen Evans.

Research taking place in Leeds could revolutionise the way cancer is treated – by bombarding tumours with tiny bubbles filled with drugs.

Experts at the University of Leeds and the city’s two main hospitals believe the use of so-called ‘microbubbles’ has the potential to significantly reduce the amount of drugs that have to be given to cancer patients and spare them the harrowing side-effects that normally come with chemotherapy.

Microbubbles are so small that tens of thousands would fit onto a single full stop – and a machine named Horizon, developed by the university team, can produce a billion in the space of just three minutes.

The university’s experts are exploring a theory that the bubbles, once injected into the bloodstream, could be used to carry cancer drugs to the exact part of the body where they are needed.

Under current treatment techniques, the drugs spread around a patient’s system, damaging healthy cells and triggering side-effects such as fatigue, hair loss and sickness.

The shell of the microbubbles, it is hoped, would stop their toxic contents coming into contact with healthy cells during their journey through the system.

Ultrasound technology would be used to keep track of the bubbles until they reached the targeted tumour, when they would be burst remotely and the drugs released.

Professor Stephen Evans, who is leading the research team, said: “There are still some hurdles to overcome to prove this can all be done safely.

“We need to refine the technology and prove that bubbles carrying drugs can be used reliably in people – but I would hope that within two years we could be having our first clinical trials with cancer patients. And that would happen right here in Leeds.”

Describing the technique that would be used at the point of delivery, Prof Evans added: “A bit like how an opera singer can crack a wine glass by hitting a certain note with their voice, we can use a specific ultrasound frequency to pop the bubbles as they reach the right place in the body.”

If the research team’s work pays off, the new method would allow cancer patients to be treated with smaller doses of drugs.

Doctors could also use some stronger chemotherapy agents that are currently off-limits because of the dangerous side-effects they might cause.

It is thought the approach could also help the treatment of conditions other than cancer, with infections potentially being fought by bubbles filled with antibiotics.

“Sometimes infections build up a protective film, which prevents the antibiotic from getting inside and fighting the bacteria,” said Prof Evans.“But bursting microbubbles releases energy which breaks up those bacterial films and enables the drug to penetrate much deeper.”

Microbubbles are already being used to improve the results of ultrasound imaging.

The bubbles can be injected into a patient’s bloodstream to give doctors a clear picture of how blood is flowing, for example around tumours or through heart defects.