Tiny Robot Armies Could Treat Brain Bleeds

In the 1966 film “Fantastic Voyage,” a team of scientists shrunk to microscopic size venture into the body of an injured scientist to repair damage to his brain.

It was, of course, pure science-fiction fantasy at the time. But that fantasy could soon become a reality (without the shrinking humans part), as researchers have created nanoscale robots that could be used to manage brain bleeds caused by aneurysms. 
 
The development could enable precise, relatively low-risk treatment of brain aneurysms, which cause around 500,000 deaths globally each year. The medical condition—a blood-filled bulge on a brain artery that can rupture and cause fatal bleeds—can also lead to stroke and disability. 
 
The development opens the door to a future where tiny robots could be remotely controlled to condut complex tasks within the human body—such as targeted drug delivery and organ repair—in a minimally invasive way, researchers contend.
 
An international research team, involving members from the University of Edinburgh’s School of Engineering, engineered magnetic nanorobots—about 1/20th the size of a human red blood cell—comprising blood-clotting drugs encased in a protective coating, designed to melt at precise temperatures.  
 
In lab tests, several hundred billion such bots were injected into an artery and then remotely guided as a swarm, using magnets and medical imaging, to an aneurysm site. Magnetic sources outside the body then cause the robots to cluster together inside the aneurysm and be heated to their melting point, releasing a naturally occurring blood-clotting protein, which blocks the aneurysm to prevent or stem brain bleeding. 
 
The research team, co-led by clinicians from Shanghai Sixth People’s Hospital affiliated to Shanghai Jiao Tong University School of Medicine in China, successfully tested their devices in model aneurysms in the lab and in a small number of rabbits. The team said that nanorobots show potential for transporting and releasing drug molecules to precise locations in the body without risk of leaking into the bloodstream—a key test of the technology’s safety and efficacy.  
 
A study detailing the nanorobots’ laboratory tests could pave the way for further developments towards trials in people and eventually improve upon current brain aneurysm treatments. Typically, doctors thread a tiny microcatheter tube along blood vessels before using it to insert metal coils to stem the aneurysm blood flow, or a mesh tube called a stent, to divert the bloodstream in the artery.
 
Researchers claim their new technique could decrease the risk the body will reject implanted materials, and curb reliance on anti-blood-clotting drugs, which can cause bleeding and stomach problems. 
The method also avoids the need for doctors to manually shape a microcatheter to navigate a complex network of small blood vessels in the brain to reach the aneurysm, a painstaking task which may take hours during surgery, researchers noted. 
 
Larger brain aneurysms, which can be difficult to stem quickly and safely using metal coils or stents, could potentially be treated using the new technique as well. 
 
The study, published in Small journal, was led by a team from the United Kingdom and China that has also developed nanorobots to remove blood clots that show potential in treating stroke.   
  
“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. Our study is an important step towards bringing these technologies closer to treating critical medical conditions in a clinical setting,” said Dr. Qi Zhou of the University of Edinburgh’s School of Engineering, who co-led the study.