Cancer-fighting nanobots made from DNA that are 20,000 times smaller than the width of a human hair could one day be used to treat tumours, a study in mice carried out at the Université de Montréal (UdeM) has found.


Currently, many cancer patients being given chemotherapy intravenously, which is the most common method, don’t consistently receive an optimal drug dosage throughout their treatment. This is due to the fact that most drugs rapidly degrade once in the bloodstream meaning repeated doses need to be given over regular intervals and also that each patient's physiology is slightly different.

This is a big problem, as administering too small a dose reduces the effectiveness of the treatment and too large a dose increases the possibility of unwanted side effects.

Now, a team based at UdeM, led by Prof Alexis Vallée-Bélisle, has come up with a potential solution using bio-inspired nanotechnology. They have built nanobots out of DNA that mimic the ability of protein transporters found in living organisms to maintain precise supplies of specific molecules to specific parts of the body.

The team developed two types of DNA nanotransporters: one to carry quinine, a medication commonly used to treat malaria, and one to carry doxorubicin, a drug currently used to treat breast cancer and leukaemia.

In experiments performed on mice using the doxorubicin nanotransporter, they were able to maintain the drug in the blood for 18 times as long as conventional delivery methods and prevent it from leaching out into unwanted targets such as the heart, lungs and pancreas.

The mice in the experiments also stayed healthier than those treated using conventional methods and didn’t suffer from weight loss – a common side effect of chemotherapy. This initial success bodes well for the future, for the treatment of cancer and for other diseases, they say.

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“For now, we have demonstrated the working principle of these nanotransporters for two different drugs. But thanks to the high programmability of DNA and protein chemistries, one can now design these transporters to precisely deliver a wide range of therapeutic molecules,” said Vallée-Bélisle.

“We envision that similar nanotransporters may also be developed to deliver drugs to other specific locations in the body and maximise the presence of the drug at tumour sites.

"This would drastically improve the efficiency of drugs as well as decrease their side effects.”

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Jason Goodyer
Jason GoodyerCommissioning editor, BBC Science Focus

Jason is the commissioning editor for BBC Science Focus. He holds an MSc in physics and was named Section Editor of the Year by the British Society of Magazine Editors in 2019. He has been reporting on science and technology for more than a decade. During this time, he's walked the tunnels of the Large Hadron Collider, watched Stephen Hawking deliver his Reith Lecture on Black Holes and reported on everything from simulation universes to dancing cockatoos. He looks after the magazine’s and website’s news sections and makes regular appearances on the Instant Genius Podcast.