When we think of robots, we have R2D2, Terminator, Transformer and your utilitarian factory or voice-activated home-bots in mind; not nanorobots that you can barely see, fighting cancer, the deadliest of human diseases. The Arizona State University (Biodesign Institute, Center for Molecular Design and Biometrics) and the National Center for Nanoscience and Technology (NCNST of the Chinese Academy of Sciences) reported a major stride in beating cancer by introducing nanorobots that are programmed to cut off the blood supply of tumors, thereby shrinking them and eventually lead to cellular death.
“we have developed the first fully autonomous DNA robotic system for a vey precise drug design and targeted cancer therapy.” Prof. Hao Yan
The study of Prof. Hao Yan and his team was published in Nature Biotechnology demonstrated the effectiveness of the “DNA origami” using breast cancer, melanoma, lung cancer, and ovarian cancer mouse models. Scientists all over the world are lauding this pioneering discovery that rocked the world February 2018. “As tumor-specific targeting of ‘payloads’ is one of the more difficult things to achieve, this looks to be a very interesting advance in this area in the fight against cancer”, said Prof. Andrew Sharrocks, Professor of Molecular Biology, University of Manchester. This is achieved through a novel DNA-based nanorobot design that acts like a Trojan Horse. These nanorobots are actually rolled sheets of DNA capable of detecting increased vascularization; a condition found in tumors. This DNA sheet binds to a receptor (nucleolin) present in the vasculature of the tumor. Once it has bound, the drug, a clotting protein called thrombin is released causing clot formation which effectively shuts down the blood supply to the tumor.
Dr. Peter Bannister, Chief Technology Officer of Median Technologies and Chair of the Institution of Engineering and Technology’s Healthcare Sector, considered this a landmark study as this predominantly non-invasive procedure that seeks and destroys targeted cancer/tumor cells can potentially improve outcomes while decreasing costs and patient risk.
Yan has 20 years research experience in the field of DNA origami. Working with DNA that is 1,000 times smaller than a human hair strand, he likens it to origami because like the paper version, it can be folded and shaped into various structures, depending on the need. The study was actually started by NCNST researchers led by Prof. Baoquan Ding working on a way to cut off blood supply using thrombin. Yan and company leveled it up by creating a fully “programmable robotic system” using a 90 nanometers by 60 nanometers DNA origami with thrombin that could accomplish the goal on its own. In a manner of speaking, it is a self-propelled, penetrating clotting agent.
“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.”
– Prof. Baoquan Ding, NCNST
How is this specificity for targeting tumor cells only (and not healthy cells) accomplished? The DNA aptamer on the surface of the DNA origami only reacts with the protein nucleolin found on the surface of tumor cells. Since these are not found on the surface of healthy cells, these are spared from destruction. Once it enters, the nanorobots work fast in releasing thrombin, its deadly cargo and start the destruction of the tumor cells in just 24 hours. In effect, it is causing mini strokes simultaneously all over the tumor. By the second day, massive thrombosis was observed and by the third day, all tumors contained thrombi in its blood vessels. After it has done its deed it is also safely degraded and eliminated from the body in 24 hours. The results are significant with 3 out of 8 mice with melanoma showing complete regression of cancer. Median survival time doubled and lung cancer, particularly aggressive in humans shrunk after two week’s treatment. Just imagine its implications for human cancer cure!
Aside from being found safe for healthy tissues in mice and miniature pig models (in vivo experiments), these nanorobots also did not migrate to the brain where there could be grave consequences. This does seem to be the frontier of modern cancer therapy. While it is still a long way from the lab to the market, this signals the beginning of conquering cancer and vascular metastasis without the adverse effects found in traditional chemo and radiation therapy.
Sources:
Arizona State University. “Cancer-fighting nanorobots programmed to seek and destroy tumors: Study shows first applications of DNA origami for nanomedicine.” ScienceDaily. ScienceDaily, 12 February 2018. <www.sciencedaily.com/releases/2018/02/180212112000.htm>.
A DNA nanorobot functions as a cancer therapeutic in response to a molecular trigger in vivo’ by Suping Li et al. published in Nature Biotechnology on Monday 12 February 2018.
https://www.ncbi.nlm.nih.gov/pubmed/29431737
