The miniature machine, modeled on the body’s own immune system, consists of cleverly folded genetic material (DNA) and can in principle be tailored to any target cell in the organism, as the developers led by shawn douglas of harvard university in boston report in the u.S. Journal "science".
So far, however, the robot has only been tested in cell cultures. Whether it can ever be used on humans has not yet been clarified. Similar approaches are also being pursued by other research groups.
The nanorobot resembles a hexagonal cage that is only 45 nanometers (millionths of a millimeter) high and 35 nanometers thick – making it about 2000 times thinner than a human hair. The cage, folded using a special technique called DNA-origami, consists of two halves held together by custom-made bars. These bars are designed in such a way that, like white blood cells, they can recognize the surface of desired target cells – such as cancer cells – and dock onto them. With docking, the latch reconfigures itself so that the nanocage swings open.
The hold can be filled with various active ingredients, which can then be transported to their specific location. In the experiment, douglas’ team loaded its nanorobots with, among other things, molecular messengers that can activate a cell’s suicide program. This program is typically disrupted in cancer cells.
In the laboratory, the researchers were able to trigger self-destruction in leukemia and lymphoma cells in this way, whereby the molecular messages also had to be tailored for the two different cancer cells. According to this pattern, different actions could be specifically triggered in desired cell types, the scientists explain.
Douglas said that the researchers, who were inspired by the function of the human immune system for their work, are now preparing tests on laboratory animals. "This will probably require an improved design to ensure stable circulation and function in the bloodstream," the researcher qualified, however. "In addition, the manufacturing costs of the device must come down."