‘NANOROBOTS’ KILL CANCER IN MICE
Custom-designed DNA nanorobots have been successfully used to shrink tumours
In a world first, researchers from Arizona State University and the Chinese Academy of Sciences in Beijing have used DNA
‘nanorobots’ to kill cancerous cells by cutting off their blood supply.
“We have developed the first fully autonomous, DNA robotic system for a very precise drug design and targeted cancer therapy,” said Prof Hao Yan. “Moreover, this technology is a strategy that can be used for many types of cancer, since all solid tumourfeeding blood vessels are essentially the same.”
The nanobots were made from flat, rectangular DNA sheets, 90 x 60nm in size. Thrombin, a blood-clotting enzyme, was attached to the surface. When delivered to the surface of a tumour, thrombin clots the blood within the vessels that feed the tumour, stems the blood flow, and kills the cancerous tissue.
Another substance, called a DNA aptamer, was then attached to the nanorobots’ surfaces. When an aptamer comes into contact with a cancerous growth, it binds with nucleolin, a protein found on the surface of tumours and not on healthy cells, allowing the bot to deliver the thrombin.
“WE HAVE DEVELOPED
THE FIRST FULLY AUTONOMOUS,
DNA ROBOTIC SYSTEM FOR A VERY PRECISE DRUG DESIGN AND
TARGETED CANCER THERAPY”
When given to a mouse that had been injected with human cancer cells, the bots travelled throughout the bloodstream, homed in on the tumours, and began working within hours.
Of the eight mice treated for melanoma, three showed complete regression of the tumours and the median survival time was doubled to 45 days. The team also tried the technique on breast, ovarian and lung cancers.
“I think we are much closer to real, practical medical applications of the technology,” said Yan. “Combinations of different rationally designed nanorobots carrying various agents may help to accomplish the ultimate goal of cancer research: the eradication of solid tumours. Furthermore, the current strategy may be developed as a drug delivery platform for the treatment of other diseases by modification of the geometry of the nanostructures, the targeting groups and the loaded cargoes,” he added.
Artist’s impressionof nanorobots
Artist’s impression of nanobots (blue) attacking a cancerous cell (green)
DNA aptamers on the nanobots attach to cancerous cells, enabling the bots to deliver their lethal payload to a cancerous tumourThrombin payloadDNA aptamer