Bio-engineers are using custom bacteria controlled by magnets to deliver cancer drugs.

Canadian researchers say their new nano-robotic agents are capable of navigating through the bloodstream to administer a drug with precision by specifically targeting the active cancerous cells of tumours.

“These legions of nano-robotic agents were actually composed of more than 100 million flagellated bacteria - and therefore self-propelled - and loaded with drugs that moved by taking the most direct path between the drug's injection point and the area of the body to cure,” explains Professor Sylvain Martel, chair of Medical Nanorobotics and Director of the Polytechnique Montréal Nanorobotics Laboratory.

“The drug's propelling force was enough to travel efficiently and enter deep inside the tumours.”

The nano-robotic agents can autonomously detect oxygen-depleted tumour areas, known as hypoxic zones, and deliver the drug to them.

This hypoxic zone is created by the substantial consumption of oxygen by rapidly growing tumours. Hypoxic zones are known to be resistant to most therapies, including radiotherapy.

The bacteria rely on two natural systems to move around within a computer-controlled magnetic field.

A kind of compass created by a chain of magnetic nanoparticles allows them to move in the direction of a magnetic field, while a sensor measuring oxygen concentration enables them to reach and remain in the tumour's active regions.

“This innovative use of nano-transporters will have an impact not only on creating more advanced engineering concepts and original intervention methods, but it also throws the door wide open to the synthesis of new vehicles for therapeutic, imaging and diagnostic agents,” Professor Martel adds.

“Chemotherapy, which is so toxic for the entire human body, could make use of these natural nano-robots to move drugs directly to the targeted area, eliminating the harmful side effects while also boosting its therapeutic effectiveness.”

The full study is accessible here.