An incredible achievement for nanomedicine was accomplished by Arizona State University scientists, in collaboration with researchers from the National Center for Nanoscience and Technology (NCNST) of the Chinese Academy of Sciences, in successfully programming nanorobots to shrink tumors 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 Hao Yan, director of the ASU Biodesign Institute’s Center for Molecular Design and Biomimetics. “Moreover, this technology is a strategy that can be used for many types of cancer, since all solid tumor-feeding blood vessels are essentially the same”.
One of the leading experts in DNA origami, Yan has been working for the past twenty years on atomic-scale manufacturing to build more and more complex structures. These incredible building blocks come from DNA, which can self-fold into a variety of shapes and sizes — all at a scale 1,000 times smaller than the width of a human hair.
In the attempt to safely destroy cancerous tumors, they chose a simple yet effective approach, starving them out.
“These nanorobots can be programmed to transport molecular payloads and cause on-site tumor blood-supply blockages, which can lead to tissue death and shrink the tumor”, noted Dr. Baoquan Ding, professor at the NCNST in Beijing.
In mouse model testing, the team used nanobots made from flat, rectangular DNA origami sheets, 90 nanometers by 60 nanometers in size. To this base, they attached a key enzyme, called thrombin. This molecule can induce blood clotting within the vessels that supply tumors, causing a sort of tumor mini heart attack and leading to tumor tissue death.
In order to program the nanobots to attack only cancer cells, they include a special payload on its surface, called a DNA aptamer, which can target specific proteins. In this case, it was nucleolin, a protein found in high amounts only on the surface of tumor endothelial cells and not on healthy cells. The nanobots worked like miniature Trojan horses, delivering their deadly payload straight inside the tumor.
Initial experiments were outstanding, proving their effectiveness. “The nanorobots are decidedly safe in the normal tissues of mice and large animals”, added Professor Guangjun Nie.
Yan and his colleagues are now looking for funding to develop this technology further, pointing that: “Combinations of different rationally designed nanorobots carrying various agents may help to accomplish the ultimate goal of cancer research: the eradication of solid tumors and vascularized metastases. 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.”
HOPE RISES With Us!