Аuthor: Аibulova Diana
Editor: Аibulova Diana
Nanomedicine - a promising young industry in the field of medicine, which opens wide opportunities for diagnosis, treatment and prevention of serious diseases by launching into the bloodstream and tissue molecule size elements of nanoparticles, a kind of nanorobots involved in the transfer of desired microelements.
Until now, the problem of promoting nanomedicine has been difficult, as the development, construction and careful monitoring of nanorobots for targeted search and destruction of cancer cells and tissues without harming healthy cells was an urgent issue.
One of the global nanomedical projects to date is the first fully autonomous robotic DNA system for very precise drug exposure and targeted cancer therapy. This technology is a strategy that can be used to fight many types of cancer. In a major study in nanomedicine, scientists at the State University of Arizona (ASU), in collaboration with researchers at the National Center for Nanoscience and Technology (NCNST) of the Chinese Academy of Sciences, have successfully programmed nanorobots to break down tumors by cutting them off from blood flow. Hao Yan, Director of the Center for Molecular Design and Biomimetics at the ASU Biosign Institute of Biotechnology and Professor Milton Glick of the School of Molecular Sciences are the main founders of the project. The technology was successfully demonstrated in mammals using breast, ovarian, lung and melanoma cancer models and was published in Nature Biotechnology magazine.
Hao Yan is an expert in the field of DNA origami, which in the last two decades has made significant progress in building increasingly complex structures of nanoscale, a thousand times smaller than the width of human hair. The technology offers hope for a revolution in medicine. The idea was based on a simple strategy - to selectively search for and isolate tumors.
This work was started about 5 years ago. NCNST researchers originally intended to cut off the blood supply to the tumor, causing blood coagulation using DNA nanocarriers. Professor Hao Yan's experience has helped to modernize the approach to make a fully programmable robotic system capable of fulfilling its mission completely independently. The nanorobots can be programmed to transport molecular payloads and cause local blood vessel clogging at a specific location, which can lead to tissue death and tumor reduction. The well-known model of benign mouse tumor became the platform for successful research: cancer cells were injected into the mouse body for aggressive tumor growth. After the tumor maturation, a group of nanobots was deployed to cut off the cancerous tissue from the bloodstream.
Each nanorobot is made of a flat, rectangular sheet of DNA-origami, the size of 90 * 60 nanometers. A key blood enzyme called thrombin is attached to the surface. Thrombin can block the blood flow in a tumor by coagulating the blood in the vessels that feed the tumor growth, causing the tumor to have a kind of mini-heart attack and causing the tumor tissue to die. On average, four thrombin molecules were attached to flat frames of DNA. The flat sheet was then rolled up like a piece of paper to make a hollow tube similar to a cylinder, then these robotic tubes were inserted into a mouse, and then they travelled all over the bloodstream, moving towards the tumors.
The key to programming a nanorobot that only attacks a cancer cell includes a special substance on its surface called a DNA aptameter. A DNA aptamer can specifically target a protein called nucleolin (nucleus protein), which is produced in large quantities only on the surface of endothelial cells of a tumor and is not on the surface of healthy cells.
Mounted on the surface of a blood vessel, the nanorobot acts as a "Trojan horse" to deliver its cargo to the tumor, exposing an enzyme called thrombin, which is the key to blood clotting.
Combinations of different rationally designed nanorobots carrying different agents can help achieve the ultimate goal in cancer treatment: eradicating solid tumors and vascularized metastases. In addition, the current strategy can be developed as a drug delivery platform for treating other diseases.
