Nanorobotic drug delivery using flagellated bacteria by team from Polytechnique Montréal
In August 2016, a team led by Sylvain Martel at Polytechnique Montréal published research in Nature Nanotechnology demonstrating that swarms of approximately 100 million flagellated bacteria, each carrying a magnetosome acting as a compass, could transport and release an anticancer drug payload preferentially within the hypoxic regions of a tumour in a mouse model.
Background
Chemotherapy works by poisoning cells that divide quickly. The problem is that it cannot tell the difference between a cancer cell and a healthy one. The drug travels through the bloodstream and damages whatever it reaches. Oncologists have spent decades trying to get around this by targeting tumours more precisely, but the body is not an easy system to navigate with a syringe.
One of the harder problems is the interior of a solid tumour. As a tumour grows, it outpaces its own blood supply. The tissue at its centre becomes hypoxic, meaning it is starved of oxygen. Conventional drugs, which arrive through the blood, struggle to reach this region. Yet those oxygen-depleted cells are often the most treatment-resistant, and leaving them untouched helps the tumour survive.
Some researchers had already shown that certain bacteria naturally move toward low-oxygen environments. The bacteria use this behaviour to find conditions that suit their metabolism. The question was whether that instinct could be put to work inside a living body, carrying medicine to places a drug alone could not reliably reach.
What happened
Sylvain Martel and his colleagues at Polytechnique Montréal, working with the Institute of Biomedical Engineering in Montreal, built a delivery system from living bacteria rather than synthetic machines. They used magnetotactic bacteria, a type of microorganism that contains magnetosomes, tiny chains of magnetic crystals that act as an internal compass. An external magnetic field can be used to steer them. The bacteria also carry their own propulsion: flagella, whip-like appendages they spin to move through fluid.
The team loaded the bacteria with nanoliposomes containing an anticancer drug. Nanoliposomes are tiny spherical capsules made of the same fatty material as a cell membrane, and they can be filled with a drug payload and carried along for the ride. About 100 million bacteria were used in each run of the experiment. The magnetic field guided the swarm toward the tumour, and the bacteria’s natural drive toward low-oxygen tissue took them the rest of the way into the hypoxic core. Once there, they released the drug.
The experiment was run in a mouse model, and the results were published in Nature Nanotechnology in August 2016. The bacteria reached the hypoxic regions of the tumour preferentially, meaning the drug was concentrated where conventional delivery struggled to go. This was a proof-of-concept result in an animal model, not a clinical treatment. Human trials were not part of this work. Even so, showing that a swarm of living, externally steered microorganisms could carry and release a therapeutic payload inside a tumour was a result that had not been shown before at this level of precision.
Why it mattered
The work demonstrated that biological microorganisms could be directed by external magnetic fields to exploit the low-oxygen microenvironment of solid tumours, a targeting mechanism unavailable to conventional systemic drug delivery. By concentrating a cytotoxic payload in oxygen-depleted cancerous tissue, the approach reduced collateral exposure of healthy cells, a longstanding limitation of chemotherapy. It established a proof-of-concept for using living, self-propelled agents as programmable drug carriers, bridging robotics, bioinformatics, and oncology.
People
Organisations
Polytechnique Montreal, Institute of Biomedical Engineering Montreal
Sources
- Magneto-aerotactic bacteria deliver drug-containing nanoliposomes to tumour hypoxic regions.Nature Nanotechnology.Primary source
- Magneto-aerotactic bacteria deliver drug-containing nanoliposomes to tumour hypoxic regions.Nature Publishing Group.Primary source
- Nanorobots to attack cancer.Polytechnique Montréal.Official
Cite this page
AI Achievements. (2016). Nanorobotic drug delivery using flagellated bacteria by team from Polytechnique Montréal. Retrieved 2026-08-22, from https://achievements.ai/milestone/nanorobots-by-polytechnique-of-montreal
@misc{achievements_nanorobots_by_polytechnique_of_montreal,
title = {Nanorobotic drug delivery using flagellated bacteria by team from Polytechnique Montréal},
author = {{AI Achievements}},
year = {2016},
url = {https://achievements.ai/milestone/nanorobots-by-polytechnique-of-montreal}
}