Xenobots: living nanorobots from frog cells
Back in 1495, Leonardo da Vinci created a drawing of living armor. And only after 425 years, Czech science fiction writer Karel Čapek first used the word “robot” in his play “R.U.R.”. Modern robots are much smarter, more complex and more mobile than the da Vinci robot, but they have common features. One of them is the material from which these amazing machines are made. When we talk about robots, we most often imagine something synthetic, not without reason in books and movies of robots are sometimes called synthetics.
However, robots can be created not only from metal, plastic or carbon fiber. Scientists from the University of Vermont (USA) decided to use dead frog cells as building materials. The resulting microscopic robots, called “xenobots,” are able to travel through the body of a living organism and perform their tasks. How exactly did scientists create artificial life, what talents can xenobots boast of, and where can such an unusual invention be applied? We learn about this from the report of the research group. Go.
Study basis
Creating a mechanism that will perform some tasks under the control of artificial intelligence is not so difficult nowadays. It is not difficult to rebuild the existing organism by changing its structure, functions or characteristics. However, creating life from scratch is not an easy task. Researchers at the University of Vermont say that synthetic materials are used in robotics for the most part because of the simplicity of their manufacture, implementation and integration. Exaggerated saying metal can always be melted, reforged, or sharpened. But living organisms, tissues and cells, i.e. living systems demonstrate the stability of structure and functions. They are very resistant to outside interference aimed at changing their behavior.
At the same time, living cells, especially embryonic ones, demonstrate amazing features that even the most developed synthetic robots cannot boast of. Embryonic cells are able to self-organize, realizing the processes of tissue development and regeneration, depending on the situation. Manipulations with this ability may allow the creation of a synthetic morphology through which new life forms can be realized, no matter how loud it sounds. Moreover, the process of cell self-organization can be supervised, thereby providing the future structure with the necessary functions and characteristics.
At the moment, there are already several methods for developing and creating individual living systems. For example, unicellular organisms can be modified by means of refactored (transformed) genomes, but this is not yet possible to implement in multicellular systems.
You can also modify the cell strand by changing the culture conditions. But in this case, control over the processes and over the structure and functions will be minimal. In contrast, there are developments in the field of bioengineering, where three-dimensional frameworks are studied. This option will give more control. But the inability to predict the behavior of an arbitrary biological structure limits this technique to the assembly of biological machines based on existing ones. In other words, it will be the same modification of what is already there, but not the creation of a new living organism.
Despite all the difficulties and obstacles, there are ways. One of them is computational search in conjunction with three-dimensional printing. Unlike machine learning, search is an evolutionary process that allows you to design the physical structure of a machine and its behavior from scratch. In addition, this method is not tied to any specific types of the structure being created or to any specific functions. The same evolutionary algorithm can be used to develop different systems: drugs, metamaterials, and even autonomous machines.
In our study today, scientists demonstrated a scalable approach to the design of living systems using an evolutionary algorithm.
Image No. 1
The new method is organized as a linear conveyor, which takes as input the description of the used biological building blocks and the desired behavior that the manufactured system should demonstrate. The conveyor continuously displays healthy living systems that implement the specified behavior in different ways. The resulting living systems are new collections of cells that have very little to do with existing organs or organisms.
Research results
The conveyor is organized as a sequence of generators and filters. The first generator is an evolutionary algorithm that discovers various ways of combining biological building blocks to realize the desired behavior. To begin with, a population of random variants of future system models is created. Each model is then recreated in a virtual environment, after which a performance rating is automatically assigned. Less productive models are deleted and overwritten by accidentally modified copies of more productive models. The repetition of this process leads to the formation of populations of diverse and non-repeating patterns.