Less than a millimetre long, the programmed organisms could one day be used to remove microplastic ocean pollution, deliver drugs, and even clean arteries.
- Stem cells bring game-changing treatments
- Researchers create the first living robots
- Scientists predict the future of xenobots
- The ethics of ‘living programmable organisms’
- The future of medical research is bright
Just a century ago, humans were likely to die from illnesses we can easily treat today, such as the flu or pneumonia. But despite medical advancements that have made these threats considerably less dangerous, scientists are still struggling to find the cure for life-threatening diseases such as cancer and debilitating conditions like multiple sclerosis. Stem cells, which have the ability to transform into almost any cell, could be the answer to humanity's greatest health challenges.
For instance, patients suffering from vision loss caused by advanced dry age-related macular degeneration (dry AMD) could soon be offered a treatment that involves injecting specialised stem cells that can repair damaged retinal epithelium cells and thus prevent blindness, which isn’t an everyday feat. The broad applications for the use of stem cells in medical treatment are further emphasised by the steady growth of the global stem cells market, the value of which is predicted to reach nearly $13 billion by 2026, up from $5.9 billion in 2018, according to Kenneth Research.
American researchers have gone a step further to create the first living robots using the stem cells of the Xenopus laevis frog, appropriately naming them xenobots. Designed by a computer algorithm, these organic robots can heal themselves when damaged, and they represent an entirely new form of life. A bridge between a computer and an organic being, xenobots could be an interlude to a world where tumours and congenital disabilities are no more.
Stem cells bring game-changing treatments
By combining stem cell research with gene editing, doctors can arrive at truly revolutionary treatments. An experimental treatment of sickle cell anaemia, for example, involves taking a small amount of hematopoietic stem cells – bone marrow cells that produce red blood cells – from a patient and replacing the mutated genes in the cells with healthy gene copies. Then, these modified cells are transplanted back into the patient, where they can spread in the bone marrow and lead to the production of healthy, and not sickled, red blood cells. Scientists have also been able to use stem cells to create organoids, simplified versions of organs such as the brain or kidneys, that contain some of the original organ’s features. Researchers can use these organoids to test medication, which allows for better predictions of how an actual organ would respond to it.
University of Pennsylvania researchers are in the process of using stem cells to grow pea-sized organoid brains that can mimic the features of human brains. Organoids can be used in testing to determine how a full-scale brain would react to a particular treatment. For example, in the event of a brain tumour, surgery is usually the first line of treatment, followed by radiation or chemotherapy. But if these treatments fail, doctors must take a sample from the tumour itself to determine the appropriate targeted therapy through genetic testing. Organoids could offer an alternative, as doctors could use stem cells from a patient’s tumour and grow them into a ‘mini-brain’, implant them into mouse brains, and test them to see their response to various treatments.
Despite the promises that the future of stem cell treatments holds, they’re currently only used to treat some blood diseases, produce skin grafts, and repair damaged corneas. Before being officially approved as a treatment, stem cells must undergo thorough clinical trials to prove not only their safety and efficacy, but also superiority to already existing therapies.
Researchers create the first living robots
Stem cell research has by no means stopped at gene-editing or organoids. A team of American researchers at Tufts University, the University of Vermont, and the Harvard Wyss Institute, funded by the US Defense Advanced Research Projects Agency (DARPA), have built living miniature robots called xenobots using stem cells from the Xenopus laevis frog. The most successful prototype has two short legs that it uses to propel itself. At the same time, a hole in another xenobot was transformed into a pouch for miniature payloads. Michael Levin, the director of the Allen Discovery Center at Tufts University, didn’t mince his words when describing the significance of this breakthrough. "These are entirely new lifeforms. They have never before existed on Earth," Levin says.
Xenobots are no bigger than 1 millimetre and were created by an evolutionary AI algorithm that first randomly generated 3D configurations of skin and heart cells. Then, the designs were virtually tested, and those with the best results were used to produce more designs. For example, a design with heart cells would be tested to see how far it could move by contracting and relaxing continuously. The researchers describe the final product of this procedure as “a living, 3D approximation of the evolved design, which possesses the ability to self-locomote and explore an aqueous environment for a period of days or weeks without additional nutrients.” Since the xenobots contain cells from frogs that usually spend their entire lifespan in aquatic environments, the researchers placed them in water and observed different patterns of behaviour – some xenobots moved in straight lines, some went in circles, and others teamed up and moved in groups.
Scientists predict the future of xenobots
It's difficult to determine precisely how xenobots are going to be used in the future, but the scientists note that “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.” As they’re programmable organisms, the possibilities for their use are vast. Presently, the robots are miniature, but the research team is planning on scaling them up, as well as building them with nervous systems, sensory cells, and blood vessels.
Apart from assisting with practical tasks that could improve day-to-day life, xenobots are opening the door to more knowledge about cell biology and human health. If scientists could build organs or other biological forms on demand, they could transform tumours into healthy tissue, stop ageing, or mend congenital disabilities. While some of these scenarios could raise concerns among the public that science is perhaps going too far, the researchers behind the xenobots say there's no need to worry that the robots will spiral out of control – they’re pre-fed lipids and proteins enough to keep them alive for only a week. Furthermore, they can’t evolve by themselves, nor can they reproduce, so they remain entirely under the control of the research team.
The ethics of ‘living programmable organisms’
Sam Kriegman, a University of Vermont PhD student and research team member, concedes that the project raises ethical questions, especially if future versions of the xenobots contain nervous systems or cognitive capabilities. The answer lies in keeping the project public, so that discussion can take place among policymakers and the broader society as well. And those with concerns that xenobots could start a robot uprising need only watch a video of these creatures to understand the improbability of this scenario.
Thomas Douglas, a senior research fellow at the Oxford Uehiro Centre for Practical Ethics, has also raised questions about the robots' moral status, such as should they be considered beings that need protection at some point? Douglas believes they should be treated ethically only if future renditions include neural tissue that allows them to experience pain, for instance.
The future of medical research is bright
Stem cell treatments are revolutionary in the sense that they have the power to remove the cause of various diseases, not just manage the symptoms. By creating living robots from animal stem cells, scientists can use them to conduct more efficient clinical trials and carefully determine the best possible treatment for a patient, which is of paramount importance for those suffering from life-threatening illnesses such as cancer. While it's too early to tell what living programmable organisms will be precisely used for, their mere existence is pointing to medical breakthroughs that will one day allow us to live in a world where incurable diseases are a thing of the past.