'Swarm of nanorobots' could treat brain aneurysms

Bots are each around a twentieth of the size of a red blood cell and encased in a coating designed to melt at precise temperatures

An image of engineered magnetic nanorobots about 300nm in diameter that can treat bleeds in the brain caused by aneurysms. PA

A swarm of tiny nanorobots could be used to treat bleeds in the brain caused by aneurysms, opening “new frontiers in medicine”, scientists say.

Researchers have already trialled the technology on rabbits, which were injected with billions of magnetic nanobots made of blood-clotting drugs.

The nanobots, which are each around a twentieth of the size of a red blood cell, are made of three parts: a magnetic core known as an iron oxide nanoparticle, which is known to be safe for medical uses and which allows the nanorobots to be remotely guided to the right spot; a clotting drug agent called thrombin to block the aneurysm; and a protective coating that prevents the thrombin from being released in the wrong area.

Researchers guided the bots to the site of the aneurysm, a blood-filled bulge that can rupture and cause fatal bleeds, strokes or disabilities, and heated them to melt their coating, releasing the drug at the exact point it could prevent or stem bleeding.

Dr Qi Zhou of the University of Edinburgh’s School of Engineering, who co-led the study, told The National: "The nanorobots are essentially dissolved in the process and become part of the formed thrombus, which should gradually shrink in size due to blood supply cut-off, and be captured by immune cells for clean-up and natural healing."

He said nanorobots are set to open "new frontiers in medicine", potentially allowing us to carry out surgical repairs with fewer risks than conventional treatments and target drugs with pinpoint accuracy in hard-to-reach parts of the body.

The technology is likely to be in use in the coming decade.

"The next steps for us would be to test this technology in larger animals such as piglets or sheep for more comparable conditions to humans, with vessel networks and blood flow.

"We need to improve our control system for robust motion of the nanorobots to reach aneurysms located deeper in the brain. It is also important to make sure this treatment is safe and effective for the body in the long term through more preclinical studies. There is more work to be done, but we believe this technology has the potential to revolutionise the way we treat brain aneurysms."

The study showed nanobots have the potential to transport drugs to precise locations without the risk of leaking into the bloodstream, a key test of the technology’s safety and efficiency, researchers said.

The bots could also reduce the need for implants in the treatment of brain aneurysms, such as coils or mesh tubes, known as stents, and curb reliance on anti-blood-clotting drugs, which can cause bleeding and stomach problems.

Aneurysms cause about 500,000 deaths globally each year and are treated by surgery which can take hours due to the need to navigate a complex network of small blood vessels in the brain.

The study, published in the nanoscience and nanotechnology journal Small, was led by a team from the UK and China.

The same team has also developed nanorobots to remove blood clots, which they said also showed their potential in the treatment of strokes.