Cancer doctors might be scaling down and getting a whole lot smaller. However, unlike the 1960s film Fantastic Voyage, the miniaturized medics will be robotic rather than human. A study published in Nature Biotechnology showed promising early results using nanobots for cancer in mice, shrinking tumors and stopping them from spreading. Although not yet tested in patients, the study opens up new areas of research into cancer treatment.
Nanobots on a Fantastic Voyage
The research team created nanoscale origami structures from sheets of DNA. At around 19nm in diameter and 90nm long, the nanobots are small enough to be injected intravenously and travel unimpeded through blood vessels. For a sense of scale, World Economic Forum reported that “Nanomachines may be tiny — 50,000 of them would fit across the diameter of a human hair — but they have the potential to pack a mighty punch in the fight against cancer.”
Autonomous and Targeted to Cancer’s Address
The key to the nanobot’s success against the tumors in the mice lies in design and targeting. TechCrunch describes how the tiny autonomous nanobots successfully went on a “seek and destroy” mission in the mice, homing in precisely on cancer and leaving healthy tissue untouched
One of the major problems with chemotherapy is that treatment often attacks non-cancerous tissue too. To avoid this, the researchers targeted the nanobots by tagging the DNA sheet with triggers that bind to cancer-specific proteins. In this study, the team used an aptamer, an oligonucleotide molecule, that binds to nucleolin, a protein expressed in tumor vessel walls. Not only did this help with targeting for the “seek” part of the nanobot mission, but it also delivered the “destroy” part too. Binding to nucleolin makes the DNA tube unroll and deliver thrombin, a protease, or proteolytic enzyme, that stimulates blood clot formation. Once in place, the nanobots triggered clots to block tumor vessels, cutting off the blood supply and killing the cancer cells.
Precise targeting means that the nanobots don’t harm healthy tissues. Studies in both the mice and also in a larger animal model, the Bama mini pig, which has physiology and immune response similar to humans’, showed clotting damage only within the tumors themselves. Rolled up inside the DNA nanobot tube, the thrombin had no opportunity to act until triggered by tumor vessel walls. The strikes worked against solid tumors in the mice such as breast, ovarian and lung cancer. Furthermore, the study found that in mouse melanoma models, the nanobots also reduced metastatic spread into the liver.
Medical Advances for Clinical Care
Since blood supply is a common feature in malignancy, the nanobots for cancer approach could be effective against a wide range of tumors. In addition to attacking a tumor’s blood supply, they’ve also been shown to kill cancer cells directly. World Economic Forum reported on light-activated nanobots that drill into tumor cells to destroy them. Precision medicine uses big data gathered in massive population studies to tailor cancer medicine for an individual perfect fit; using this information to match drug to tumor and deliver it by nanobot might increase chemotherapeutic success.
Furthermore, as a drug delivery device that can be targeted with precision, these medical advances could treat more than just cancer. Matching aptamers on the DNA nanobots to disease pathogen proteins and other pathological markers could help doctors deliver medicine just where it is needed inside the patient.
Nanobots Launch Into the Future
Since these nanobots for cancer have not been tested in patients yet, nobody can predict when we’ll see them as treatment. The research reported took five years to complete and it’s still at the animal modeling stage. However, according to futurist Ray Kurzweil, we should see more and more nanobots in everyday life. He predicted that by 2030, nanobots along with software advances will cure most diseases, so who knows what the future holds.