Domestic researchers have succeeded in developing a cell robot that autonomously moves by directly utilizing components of living organisms such as cells. This is expected to be used as fundamental technology for precise drug delivery and next-generation cell-based therapies.
A research team led by Professor Choi In-sung of the Korea Advanced Institute of Science and Technology (KAIST) announced on the 30th that they have developed a self-propelled cell robot that uses urea (CO(NH₂)²), a byproduct of living organisms, as fuel, without external power devices or complex mechanical structures. Urea is a waste product generated during the breakdown of proteins in most animals, including humans. The kidneys filter blood and excrete urea into urine.
The researchers focused on "yeast," which is an organism that can be easily and stably obtained, has the potential to utilize ethanol produced as a byproduct, and can generate substances autonomously without complex external devices. Yeast, used in baking and makgeolli fermentation, generates alcohol (ethanol) as a byproduct during the metabolic process of breaking down glucose, and the researchers developed fundamental technology that utilizes the ethanol produced at this time to form a biocompatible nanoshell on the yeast surface.
In particular, the chemical methodology developed this time is designed to allow for continuous nanoshell formation even while yeast grows and divides, creating asymmetric cell-shell structures naturally according to changes in cell shapes. For example, a shell that completely encases the dividing cell may form, but structures where the shell is formed on the mother cell portion and not on the daughter cell portion are also created.
The researchers attached urea-decomposing enzymes to the nanoshell encasing the cell and observed the movement of the cell robot. The urea-decomposing enzymes provide the driving force for the cell robot to move autonomously. As a result, the researchers confirmed that the asymmetric structure of the cell robot exhibited a clearer directional movement.
The cell robot developed this time can propel itself using only the substances present around the cell and does not rely on complex external control devices such as magnets or lasers, making its driving mechanism much simpler and biocompatible. Additionally, a variety of enzymes can be chemically attached to the nanoshell, allowing for the expanded development of cell robots that utilize various biological substances as fuel.
Kim Na-young, a doctoral student in the Department of Chemistry at KAIST and the first author of this study, said, "Self-propelled cell robots are a new concept platform with the ability to sense, respond to, and move autonomously in their environment, and they could play an important role in targeted cancer treatment and precise drug delivery systems in the future."
This research was published online in the international journal "Science Advances" on the 25th.
References
Science Advances (2025), DOI: https://doi.org/10.1126/sciadv.adu5451