Corkscrew-shaped microrobot that uses a helical propeller to swim through blood vessels and clear blockages with clot-busting drugs is developed by scientists
Blood clots might be soon be cleared by using microscopic robots with screw-like propellers that swim through blood vessels bearing blockage-busting drugs.
Developed by engineers from the Chinese University of Hong Kong, the microrobot design was inspired by the tails of bacteria like E. coli.
The tiny robot and its propeller are driven by the application of an external magnetic field — and it is capable of moving with and against the direction of the blood flow.
Tests in a fake vein filled with pig's blood showed the robot makes its clot-dissolving 'tissue plasminogen activator' cargo five times more effective than the drug alone.
The robot's rotor, the team said, may help to circulate the drug around the blockage site — better breaking up the clots and reducing the risk of large fragments.
These are a risk when using the drug treatment alone — and with catheter-based alternative approaches — and can lead to additional blockages 'downstream'.
As it is hard to navigate the robots long distances through the body, the researchers cautioned, the approach might be better applied to more accessible clots.

Blood clots might be soon be cleared by using microscopic robots with screw-like propellers that swim through blood vessels bearing blockage-busting drugs. The tiny robot and its propeller are driven by the application of an external magnetic field — and it is capable of moving with and against the direction of the blood flow

Developed by engineers from the Chinese University of Hong Kong, the microrobot design was inspired by the tails of bacteria like E. coli (pictured). Tests in a fake vein filled with pig's blood showed the robot makes its clot-dissolving 'tissue plasminogen activator' cargo five times more effective than the drug alone
The study was conducted by roboticist Li Zhang and his colleagues at the Chinese University of Hong Kong.
'The helical structure is just like a propeller, so [the robot] can deliver the cargo from point A to point B,' Professor Zhang told the New Scientist.
'If you want to deliver some other thing that's not a drug, that’s also possible. For example, therapies based on stem cells, or localised heating to kill cancer cells.'
To monitor the robot's progress up the synthetic vein in their lab tests, Professor Zhang and his colleagues used so-called ultrasound Doppler tracking, which works by measuring the reflection of sound waves passing through the blood.
Pierre Gélat — a mechanical engineer from University College London who was not involved in the present study — told the New Scientist that 'The ability that they have to steer the robot in in-vitro environments is quite nice.'
'The challenges are in finding out whether this will fulfil unmet clinical needs further down the line and how you get there as well.'

The robot's rotor, the team said, may help to circulate the drug around the blockage site — better breaking up the clots and reducing the risk of large fragments. Pictured: a clot
With their initial study complete, the researchers are now looking to conduct further trials of the microrobot in more realistic settings.
They will also be working to demonstrate that the design might indeed be used safely with the blood vessels of a real human patient.
The full findings of the study were published in the journal ACS Nano.
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