Canadian scientists say they have found a way to direct special bacteria to carry chemotherapy drugs straight into the most active part of a cancerous tumour. That could lead to more effective cancer treatments with lower doses of drugs and fewer side-effects.
Chemotherapy drugs are designed to be highly toxic in order to kill fast-growing cancer cells. But currently, their effectiveness is limited because very little of traditional drugs actually makes it into cancerous tumours — most of it ends up in the rest of the patient's body, causing nasty side-effects, says Sylvain Martel, a professor of computer engineering at Polytechnique Montreal.
Martel, who holds a Canada Research Chair in nanorobotics, has been working for 15 years on ways to direct drugs to a tumour.
The solution he originally envisioned was using tiny robots — nanorobots — that humans could direct using magnetic fields to swim through blood vessels and deliver drugs to a particular location.
Unfortunately, he said, "This is way beyond technology.… We cannot build this kind of nanorobot."
So instead, Martel turned to nature — could there be bacteria that could do the same job?
It turns out there are. Bacteria called magnetotactic cocci are equipped with a natural, built-in compass needle made of iron that helps them navigate as they swim through water using whip-like tails called flagella. That means they can be directed using a magnetic field.