From science fiction to reality: Xenobots are redefining biotechnology

What is a Xenobot?

Xenobot is a robot-like being that is created from living cells. Unlike the synthetic machine robots that we used to know, the xenobot is made through some biotechnology procedures and with organic cells.

It is therefore known to be the first living programmable robot built with the active contribution of artificial intelligence and biology. The xenobot is neither our usual traditional robot nor a plant or animal, but it is a tiny microorganism that can be programmed and configured to carry out a certain task or perform a function.

Generally, the xenobot is known to be 1mm long or less, and it is made from the stem cells of an African frog (Xenopus laevis) which forms the basis from which its name is derived. The xenobot moves in a linear and circular direction, and it could clump together to move in the same pattern or direction.

How is the Xenobot created?

After several years of development in Robotics, Biotechnology, and synthetic biology, scientists were concerned about how they could develop living cells that could perform a certain task. This then led some researchers at Tuft University and the University of Vermont to investigate what we now call the xenobot.

In doing this, they collected some stem cells from the embryo of a clawed African frog. The cells were then differentiated into skin cells and heart cells. The skin cells were to provide structure to the bio-robot while the heart cells relax and contract to aid movement. The whole idea of this research was to manipulate and create living cells capable of carrying out a  specific function and having a locomotive ability.

To create the xenobot, a supercomputer was programmed with an evolutionary algorithm with the aim that it'll produce different designs of cell configuration.

Next, the researchers needed to test these designs to check which of them will suit the purpose for which they were created. And so, the supercomputer was used to detect the cell designs that are capable of moving toward an object and those that were not. With this, the researchers were able to find out virtual designs that could move and perform some functions.

But that wasn't all, the researcher had to replicate the virtual procedure manually. And so skin cells and heart cells of frogs were obtained and were joined together using microsurgery tools and following the designs that were successful virtually. With the use of tiny forceps and electrodes, researchers joined thousands of cells together one after the other under the microscope.

Although it wasn't a simple process, the fact that cells have an inherent capability of sticking together made the whole procedure more seamless. After having completed the whole procedure, these researchers were able to build a xenobot that is capable of moving in a direction and circles.  

At first, xenobot could only live for seven to ten days, but with more advancements and research by scientists, it is now capable of healing themselves and living for a long time.

Potential applications of Xenobots

In their original 2019 paper, the scientists set out their hope that one-day xenobots could be programmed to perform useful functions. According to the researchers, "advances in machine learning, soft body simulation, and bioprinting are likely to broaden the potential applications to which it may be put in the future. Applications could be numerous, given the ease of expressing novel proteins and synthetic biology pathways and computational circuits in Xenopus cells."

Given their nontoxicity and self-limiting lifespan, they could serve as a novel vehicle for intelligent drug delivery (28) or internal surgery (29). If equipped to express signaling circuits and proteins for enzymatic, sensory (receptor),and mechanical deformation functions, they could seek out and digest toxic or waste products, or identify molecules of interest in environments physically inaccessible to robots.

If equipped with reproductive systems (by exploiting endogenous regenerative mechanisms such as occurs in planarian fissioning), they may be capable of doing so at scale. In biomedical settings, one could envision such biobots (made from the patient's own cells) removing plaque from artery walls, identifying cancer, or settling down to differentiate or control events in locations of disease. A beneficial safety feature of such constructions is that in the absence of specific metabolic engineering, they have a naturally limited lifespan.

Fighting against cancer, heart disease, and other disease

Xenobots could one day be a very useful tool in the fight against cancer. In the future, perhaps "biobots" made from the patient's own cells could be designed to seek out and destroy cancer cells or to deliver targeted immunotherapy directly to the affected cells.

Using bots made from the patient's own cells would reduce or eliminate the chances of rejection or other complications.

Such biobots could also potentially be used to remove plaque from artery walls or differentiate or control cell function events to eliminate certain types of disease. One safety feature of such biobots would be that "in the absence of specific metabolic engineering, they have a naturally limited lifespan."

Apart from the treatment of cancer and heart disease, scientists had also claimed that xenobot could also one day be capable of delivering medicine to some particular region of the body or helping fight diseases that affect some crucial body parts. This will particularly be made possible because of the tiny nature of xenobot which makes it easier for them to reach any part of the body.

Purifying water bodies 

The numerous industrial activities in our world today have brought about the release of harmful chemical wastes and microplastics into almost every body of water on the planet. While some of these waste materials can be removed through mechanical or other means, many types of pollution are almost impossible to eliminate. One such that cannot be easily removed is the microplastics present in every water system on the planet.

The researchers suggest that Xenobots could one day be programmed to "seek out and digest toxic or waste products and microplastics, or identify molecules of interest in environments physically inaccessible to robots." The bots' ability to replicate could also be exploited to allow them to undertake this function at scale.

Detect and clean up the harmful nuclear matter

Additionally, it has been proposed that xenobot could also be able to detect harmful radioactive elements in the environment. And apart from that, it will be able to get rid of or clean up nuclear materials from places where they aren't wanted. 

Ethical considerations surrounding the use of xenobots

Xenobots could well be a valuable tool in the future. However, there are also a number of ethical issues surrounding the use of living robots that are of concern to bioethicists. As Nita Farahany, Duke University professor of law and philosophy, told Smithsonian Magazine, "Any time we try to harness life ... [we should] recognize its potential to go really poorly." After all, altering complex systems like cells can lead to unintended consequences. Concerns include:

●     It has been argued that xenobots could begin to malfunction or develop new "programming" and perhaps even develop into more complex life forms. Therefore, there should be guidelines to prevent this, if possible.

●     Since xenobots can also potentially be used to introduce life-saving medicine into the human body, they could also be manipulated to transport harmful substances into the body, such as harmful drugs or poisons.

●     There had also been arguments involving the creation of organisms from human stem cells - which can be harvested from human embryos. Guidelines on the harvesting of stem cells could forestall this. In fact, there may come a time when everyone has stem cells harvested at birth from their umbilical cord, and stored up to create personal bots. However, this also comes with its own set of ethical considerations - such as how to manage the cost.

●     It had also been argued that for us to fully maximize the usefulness of this Biotechnology, it could become necessary to use xenobots to carry out complex tasks. Scientists could therefore need to develop xenobots with nervous and sensory cells,machines which make them closer to sentient beings.

●     Questions may arise in patenting xenobots. Are they a living organism? If so, can they be patented? And if they can't be patented, how can they be protected as intellectual property?

●     Xenobots are neither machine nor living things. They exist in an undefined between state. This could lead us to question our definition of living and non-living organisms. 

●     Also, in the future, xenobots could even be used to alter body systems, including reproductive, nervous, and circulatory systems - perhaps extending life or giving us 'superpowers.' It, therefore, becomes more important to redefine what we term living organisms.

On the whole, it is crucial that, as scientists continue to experience more advances in synthetic biology, regenerative medicine, and Robotics, more ethical rules and procedures should be provided to guide them in the use of xenobots.

Future of Xenobots and Biotechnology 

With the valuable importance which xenobots had been proposed to carry out, having a stay with us and becoming part of our future is crucial and possible.

In the medical field alone, xenobots have the potential to provide treatment for some intractable diseases. The fact that we already established that this living machine could help fight against some ailments potentially makes them an essential tool that must be part of us. Apart from that, our environment could benefit from those tiny living machines in order to be intact, preserved, and healthy.   

While we can't underestimate the value xenobot would render to our lives, which inherently is the reason they should be part of our future, ethical codes and standards that would guide us against their harmful use need to be developed under close consideration of their benefits and harms. 

Conclusion

With our ever-changing world of robotics and biotechnology, we should expect more advanced xenobots in years to come. Not only could xenobots be a great living tool in medicine, but they could even help in the fight against global warming.