Researchers at Tel Aviv University have developed a hybrid micro-robot the size of a single biological cell that can be controlled and navigated using either electricity or magnetism. The device is able to navigate among different cells in a biological sample, distinguish between different types of cells, identify whether they are healthy or dying and then transport the desired cell for further study, such as genetic analysis.
It can also transfect (artificially introduce DNA or RNA into cells, using means other than viral infection) a drug or a gene into the captured targeted single cell. According to the researchers, the development could help promote research in the important field of “single cell analysis” and be used for medical diagnosis, drug transport, surgery and environmental protection by cleaning polluting particles from the environment.
The innovative technology was developed by Prof. Gilad Yossifon from TAU’s School of Mechanical Engineering and Biomedical Engineering Department, post-doctoral researcher Dr. Yue Wu and student Sivan Yakov, in collaboration with Dr. Afu Fu, a post-doctoral researcher at the Technion-Israel Institute of Technology. The research was published in the journal Advanced Science under the title “A Magnetically and Electrically Powered Hybrid Micromotor in Conductive Solutions: Synergistic Propulsion Effects and Label-Free Cargo Transport and Sensing.”
Yossifon explained that micro-robots (sometimes called micro-motors or active particles) are tiny synthetic particles the size of a biological cell that can move from place to place and perform various actions – for example, the collection of synthetic or biological cargo – autonomously or through external control by an operator.
“Developing the micro-robot’s ability to move autonomously was inspired by biological micro-swimmers like bacteria and sperm cells,” he said. “This is an innovative area of research that is developing rapidly, with a wide variety of uses in fields such as medicine and the environment and as a research tool.”
Researchers used micro-robots to capture single blood and cancer cells
As a demonstration of the micro-robot’s capabilities, the researchers used it to capture single blood and cancer cells and a single bacterium. They showed that it was able to distinguish between cells with different levels of viability, such as a healthy cell, one damaged by a drug or a cell that is dying or dying in a natural “suicide” process (apoptosis). Such a distinction may be significant, for example, when developing anti-cancer drugs. After identifying the desired cell, the micro-robot captured it and moved the cell to where it could be further analyzed.
Another important innovation is the ability of the micro-robot to identify target cells that are not labeled. The micro-robot identifies the type of cell and its condition, such as degree of health, using a built-in sensing mechanism based on the cell’s unique electrical properties.
“Our new development significantly advances the technology in two main aspects – hybrid propulsion and navigation by electric and magnetic mechanisms that are very different,” said Yossifon. “In addition, the micro-robot has an improved ability to identify and capture a single cell – without the need for tagging – for local testing or retrieval and transport to an external instrument. This research was carried out on biological samples in the laboratory for in-vitro assays, but the intention is to develop in the future micro-robots that will work also inside the body, for example, as effective drug carriers that can be precisely guided to the target.”
The researchers explained that the hybrid propulsion mechanism of the micro-robot is of particular importance in physiological environments, such as in liquid biopsies.