Scientists use nanorobots to attack and kill cancer in mice
The discovery
A holy grail of nanomedicine has been to develop nanorobots to fight disease inside of us. A new study published in the journal Nature Biotechnolgy represents a huge advance in the development of nanorobots to fight cancer. Scientists in China and Arizona have created a fully autonomous nanorobot that can destroy cancer in mice. Dr. Hao Yan, a distinguished professor of chemistry and biology from Arizona State University, says it does this by precisely targeting tumours and cutting off their blood supply - without harming healthy cells. These nanorobots are a thousand times smaller than the width of a human hair.
The nanorobots
Dr. Yan and his colleagues created these nanorobots using DNA origami, which uses single-stranded DNA to create self-assembling materials in different forms. "In this case, it's a robot in the form of a nano-cage," says Dr. Yan. "You can imagine there is a cage like structure made out of self-assembling DNA and inside of the cage we can encapsulate this protein molecule called thrombin. And outside of the cage, we decorate along the seam another piece of DNA called aptemer that can respond to protein expressed in the tumour micro-environment, which can open up the cage, expose the thrombin, to act on the blood and clot the blood and stop the nutrients."
Thrombin is a drug that causes blood to clot, which when delivered directly to the tumours, will create a clot that starves the tumour of its nutrients. Dr. Yan says he sees this DNA nanorobot as a platform technology that can be altered to recognize different biomarkers or add different drugs, like chemotherapy, or antibodies into the nano-cage for delivery.
Testing the nanorobots
They tested these DNA nanorobots on mice with a few types of tumour models, including human breast cancer, melanoma, ovarian cancer, and lung cancer. "It turned out this nanorobot can be delivered and target to this tumour, and regress the tumour, and increase the survival of the mice." In the melanoma models, they found that in three out of the eight mice they tested, the tumours completely disappeared. Dr. Yan says for the other types of cancer, they saw a doubling of the survival rate from 20 to 40 days.
"Within eight hours, the robot will get aggregated around the tumour to start to do the function to cause the blood to clot. So it takes 8-24 hours to take effect, and then you observe the tumours start to shrink."
Dr. Yan says they are currently trying to commercialize the technology in hopes of testing it in humans in 2-5 years.