Nanobots smaller than a red blood cell could soon be navigating through our bloodstream towards cancerous tumours where they would deposit life-saving medicine more safely and efficiently than traditional methods such as chemotherapy.
The tiny nanobots are being developed at Acoustic Robotics Systems Lab at the ETH Zurich public research university in Switzerland where Professor Daniel Ahmed is leading a team of researchers developing the potentially revolutionary technology.
Professor Ahmed told Real Press in an exclusive interview: “The objective of the research is to develop nanorobotics that can be manoeuvred through a patient’s bloodstream using ultrasounds.” He added: “This will allow us to target specific diseases such as tumours and blood clots by using the nanobots to deliver medicine directly to the target site.”
Professor Ahmed explained that the issue with traditional medicine is that once injected or swallowed its direction is determined by the flow of the bloodstream. He described these medicines as “passive particles” as they are essentially at the mercy of the bloodstream once inside the body.
The first line of defence against cancer remains chemotherapy, which damages areas of the body. What Professor Ahmed’s team is developing has the potential to move more specifically and therefore target cancerous cells. Professor Ahmed and his team have developed nanobots encased in a polymer shell that can be moved using ultrasounds.
One of the developers’ biggest challenges was getting the nano-swimmers to move against the flow of the bloodstream in the correct direction. Professor Ahmed said that to overcome this obstacle, he took inspiration from the way sperm travels by sticking to the vagina’s stationary walls which they then use to guide their forward movement.
These nanodevices group together in the bloodstream forming ‘microswarms’ of tiny swimmers. As seen in the footage, these groups of swimmers can then be pushed against the blood vessels’ wall using ultrasound.
Professor Ahmed said: “Clusters of the nano-swimmers are pushed towards the blood vessel walls where resistance is lower.” He added: “The flow of blood in the vessels is not affected as the ultrasound force exerted to push the swimmers is very low.” The swimmers are then moved along the blood vessel walls using ultrasound towards the target area, a tumour or blood clot.
Once the devices arrive at the target area, they can be “given a shake” using ultrasound at which point they release their medical payload.
One of the main goals of the research is to treat an extremely aggressive form of cancer that forms in the brain known as glioblastoma. Only six percent of patients currently diagnosed with this type of cancer survive more than five years after diagnosis. Traditional drugs struggle to reach these tumours, which destroy blood vessels in their proximity.
So far the nano-robots have been tested – with success – on zebrafish and now Professor Ahmed wants to move on to testing them on mice because the small freshwater fish do not have a mature blood-brain barrier, unlike mice.
Out of all the methods for controlling nano-swimmers, including magnets, chemicals and light, Professor Ahmed believes ultrasound is the best option as “ultrasound waves can penetrate deep into the body and have been shown to be safe”. He added: “The technology is also relatively inexpensive and can also be found in the majority of hospitals and clinics.”
He believes that this cutting-edge medical technology will not be available only in rich countries and that it could also be viable in poorer nations. The polymer shell that carries the nano-bots breaks down in the bloodstream without causing any harm to the patient, and therefore removing the nanorobots after treatment is not a concern.
The research still faces many obstacles, but Professor Ahmed is confident that this technology will be used to treat many types of life-threatening diseases in the not so distant future.