Current cancer therapies are limited by the challenge of delivering medicines deep inside tumours while sparing healthy tissue, a barrier that must be overcome to realise the promise of targeted and personalised medicine. Dr Ambarish Ghosh, professor at the Indian Institute of Science (IISc) Bangalore, has addressed this challenge with magnetic nanorobots which can travel through blood, dense tissue and even cells. This platform has the potential to transform cancer care through targeted, minimally invasive therapies that reduce side effects, shorten recovery and lower costs.He was awarded the 2025 New York Academy of Sciences and Tata Sons’ Transformation Prize for his efforts in the space. He spoke to Rinku Ghosh about how these nanorobots work, as well as the development of the imaging tools that will let doctors see and guide the nanorobots in real time during diagnosis and treatment.How can nanobots reach deep inside the cancer tissue? Nanobot attaching to a cancer cellThe nanorobot we developed mimics the movement of bacteria with a little helix-shaped tail. It functions like a propeller in a boat or a corkscrew as they travel through different media. As the helix turns, the object moves forward like a coiled spring. In our device, the helix has a little magnet attached to it to create magnetic fields that mimic the drilling motion.These nanobots function as nanoswimmers and effectively become a delivery truck to deliver the drug to the targeted tissue. Either the surface or the tip is coated with the drug. The bulk of the body is made with silica, which is compatible with the human body, while the magnetic material is iron, which tops the helical nanostructure, all of which are already in use in medical nanobots. Magnetic nanobots mimicking helical flagellum bacteria treating a cancerous cellThe magnetic field transports the nanobot precisely to the targeted issue, after which it can best respond, based on its specific properties that can be defined according to the issue. The nanobot can preferentially bind itself to cancer cells after penetrating their environment without affecting non-cancerous tissues.For instance, the nanobot could use the magnetic field to treat hypothermia magnetically, in which it generates localised heat exceeding 42° C to destroy target cells while sparing healthy tissue.The nanobot has been effective against cancer cells and certain bacteria. So the nanobot itself can become a drug.Story continues below this adBy adding certain elements to the helix, the nanobot may also be used a beacon that can light up during an MRI, helping the oncosurgeon pinpoint the tumour and use targeted therapies. Thus, these nanobots are multi-functional.What type of cancer has the nanobot been effective against?It has worked efficaciously on ovarian and breast cancer cells, particularly in deep-set cancers in dense breast tissue, which may not be visible in even the most advanced scans. We are fairly confident that it can work on other cancers as we continue to test further.The nanobots have already proven effective against bacteria, and we are already looking at certain low-hanging applications in dentistry, such as root canal treatments. A root canal infection happens when a stubborn and antimicrobial-resistant E.faecalis bacteria invade the tooth’s inner pulp, causing inflammation or decay. Nanobots in this instance have proven to be a pain-free alternative to the conventionally used sodium hypochlorite, the gold standard irrigant in root canal procedures. Sodium hypochlorite is used to disinfect canals, kill bacteria and dissolve infected pulp/necrotic tissue. This is not 100 percent effective in killing the bacteria and can severely harm surrounding soft tissues if it goes beyond the tooth apex, causing intense pain and swelling.Story continues below this adWe have seen that nanobots could potentially even rebuild and remineralise the teeth. For this, we are already doing clinical trials as they have been 100 per cent effective in animal experiments.When do you see the nanobots being applicable for clinical use?So far, we have worked on cell cultures. For scientific rigour, we need to do animal experiments and clinical trials. The challenge will be to rationalise costs as they depend on scale and demand.I do not foresee anything here which is too expensive, considering we are using standard nanotechnology ideas and concepts, as well as routine items used in the semiconductor industry. We do not require expensive, super-magnetic superconducting magnets like those used in MRI, and can rely on simple electromagnets, which are relatively easier to make and build.Story continues below this adThe real challenge is to make a market-friendly adaptation and find acceptability among both clinicians and patients.We have multiple US patents, and there is a lot of interest in the US. We are planning our own startup. We are awaiting approval for use of nanobots in dentistry.