Magnetic bacteria used to deliver cancer drugs deep into tumours

Researchers in Montreal have developed a new way of administering cancer-fighting drugs directly into tumours, using something they call “bacteria-based nanorobots.”
The approach has so far been successfully tested only in mice, but the researchers say the new technique could be an effective way to fight resistant tumours that are currently considered not curable.
Researchers from Polytechnique Montréal, Université de Montréal and McGill University worked for 15 years on the find, and just published the results of their work in the journal Nature Nanotechnology.
The head of the research team, Prof. Sylvain Martel, the director of the Polytechnique Montreal’s NanoRobotics Laboratory, says current injectable chemotherapies don't always get to where they need to go. As the drugs move through the bloodstream, they can also damage healthy cells along the way, leading to side effects such as hair loss and nausea.
“So we thought that if we could navigate it directly from point A to point B where we need to do the treatment, exactly inside the tumour, all those agents would become extremely efficient,” Martel told CTV Montreal.
The bacteria-based nanorobots he helped develop use Magnetococcus marinus bacteria, which contain magnetic, metallic crystals. That means they can be injected close to the tumour site, and then guided by a computer-controlled magnetic field to bring anti-cancer drugs to the tumour cells.
The bacteria the team developed can also propel themselves with their flagellums, which are whip-like tails that propel them quickly where they need to go, says research team member Dr. Te Vuong, who is director of radiation oncology at Montreal’s Jewish General Hospital.
“One of the reasons they are the perfect vector is because they can be loaded with any drugs that we want,” Dr. Vuong said.
In the research just published, Martel’s team were able to use magnetic field to guide bacteria nanorobots directly into colorectal cancer tumours of mice.
Once inside, the bacteria naturally gravitate toward low-oxygen areas of tumours. These areas are where tumour cells are rapidly proliferating, thus depleting the cells’ oxygen. It is these tumour zones that are known to be most resistant to chemotherapy and radiation, yet they are also the areas that are responsible for metastasis — the spread of cancer through the body.
Martel says the bacteria they created are as close to actual tiny robots as can be.
“When you’ve got something with propulsion, navigation, and sensors, it starts looking like the nanorobots of the future,” he said, adding: “…They behave exactly like futuristic nanorobots and deliver the drug exactly where the drug will be the most effective,” he told CTV News Channel.
Not only could these new bacteria-based nanorobots be used to deliver chemotherapy or immunotherapy drugs, they could also be used as vehicles to deliver imaging and diagnostic agents through the body.
The research team still has to determine whether the bacteria they have been working with are safe for humans, but they're optimistic that clinical trials will begin sometime in the next five years.