They successfully test a system in mice that fights #cancer by letting the tumor starve without attacking healthy cells.
The films Fantastic Voyage (1966) and The Imaginary Chip (1987) imagined what it would be like to put a miniature manned submarine inside a person capable of traveling through the bloodstream to repair the damaged tissues of a brain. For years, that same concept, that of miniaturizing treatments and directing them towards a specific part of the human body, is being investigated in various laboratories to detect and fight diseases, with an eye especially on cancer.
The advances, like the one presented this week by a team of researchers from the US and China, are promising and suggest that we are not far from making these precision treatments possible thanks to the so-called nanomedicine. Specifically, the team led by the Chinese Hao Yan, of the Institute of Biodiseño of the University of the State of Arizona (ASU), in the USA, assures to have tested with success in mice some tiny robots programmed to destroy #tumors.
The mission of the nanorrobot is to prevent the blood that feeds it from getting into the tumor and allowing it to grow. JASON DREES / ASU
The details of his study, conducted in collaboration with the National Center for Nanoscience and #Technology (NCNST) of the Chinese Academy of Sciences, have been published in the journal Nature Biotechnology .
These nanorrobots, a thousand times smaller than the thickness of a human hair , were injected into the bloodstream of the mice. According to Hao Yan, it is the first fully autonomous robotic DNA system, designed to deliver drugs very precisely in cancer therapy. “This technology is a strategy that can be used to treat many types of tumors,” says the scientist, who says they have tested their technique in cancerous cells of melanoma, breast cancer, ovarian cancer and lung cancer.
Yan, an expert in a field known as DNA origami, has based his robots on this technique, which allows you to bend DNA just like you do with paper. It is about developing structures on the atomic scale that can be folded and adopt different shapes and sizes . In the last two decades, more and more complex structures have been obtained with applications in computers, electronics and medicine.
Five years ago they began to work with their minds set to solve the biggest obstacle that these tiny systems have: how to make the #nanorobots only destroy cancer cells and not damage healthy tissues?
The tumor dies of hunger
His strategy was to locate the tumor and kill him by starving him, so the mission of the nanorobots was to prevent blood from reaching him .
First they introduced human cancer cells into a mouse so that the animal developed an aggressive tumor. When it grew enough, they injected the intravenous nanorobots. Each one is made from a DNA origami sheet that measures 90 by 60 nanometers. On its surface they placed an enzyme called thrombin, which is part of the blood’s clotting process and is able to block the tumor by cutting off the supply of the blood vessels that feed the tumor and allow it to grow.
The nanobot was injected into the mouse and traveled through its bloodstreamuntil it reached the tumor. In order to prevent it from attacking healthy cells, they placed a DNA aptamer (a nucleic acid) on its surface to specifically recognize a protein, called nuclein, that is not present in healthy cells.
It releases the enzyme thrombin to coagulate blood and an aptamer that recognizes a protein that is not present in healthy cells. JASON DREES / ASU
For Nabil Djouder, head of the Group of Factors of Growth, Nutrients and Cancer of the National Center for Oncological Research (CNIO), “this work made with DNA nanorrobots is a very important advance because they have achieved a molecule that recognizes cancer cells and has managed to generate a necrosis in the tumor “. However, he adds, the great limitation of this technique is that the models of cancer in mice are not models of tumors very real or comparable to those suffered by humans: ” Nude mice that have no immune system and to which cells are injected carcinogenic that have been cultivated in vitro . This work does not recapitulate the important stages of cancer development in a person“, Djouder explains to EL MUNDO in a telephone conversation.
The CNIO scientist, without any connection with this study, remembers that this type of therapies has already been used “to treat skin cancers because it can be done topically, without the need to use a technique as invasive as that needed to combat other tumors. ”
Sebastian Thompson, a researcher specializing in #nanotechnology in the group Djouder CNIO, also believes that it is “a very interesting work from the point of view of nanotechnology, as they have achieved the nanoparticles interact with the tumor. However, as occurs with all nanoparticles, these also have limitations . ”
In his opinion, there is still “a long way to go to be used in humans.” There is talk of about 30 years for this technique to be available, but we will have to see what progress is made in the next 10 or 15 years.