Xenobots (living robots made from African frog (Xenopus laevis) frog cells) can now self-replicate. First mentioned here in a June 21, 2021 posting, xenobots have captured the imagination of various media outlets including the Canadian Broadcasting Corporation’s (CBC) Quirks and Quarks radio programme and blog where Amanda Buckiewicz posted a December 3, 2021 article about the latest xenobot development (Note: Links have been removed),
In a new study, Bongard [Joshua Bongard, a computer scientist at the University of Vermont] and his colleagues from Tufts University and Harvard’s Wyss Institute for Biologically Inspired Engineering found that the xenobots would autonomously collect loose single cells in their environment, gathering hundreds of cells together until new xenobots had formed.
“This took a little bit for us to wrap our minds around,” he said. “There’s no programming here. Instead, we’re designing or shaping these xenobots, and what they do, the way they behave, is based on shape.”
“We take a couple of thousand of those frog cells and we squish them together into a ball and put that in the bottom of a petri dish,” Bongard told Quirks & Quarks host Bob McDonald.
“If you were to look into the dish, you would see some very small, what look like specks of pepper, moving about in the bottom of the petri dish.”
The xenobots initially received no instruction from humans on how to replicate. But when researchers added extra cells to the dish containing xenobots, they observed that the xenobots would assemble them into piles.
“Cells early in development are sticky,” said Bongard. “If the pile is large enough and the cells stick together, the outer ones on the surface will grow very small hairs, which are called cilia. And eventually, after four days, those cilia will start to beat back and forth like flexible oars, and the pile will start moving.”
To persist, life must reproduce. Over billions of years, organisms have evolved many ways of replicating, from budding plants to sexual animals to invading viruses.
Now scientists at the University of Vermont, Tufts University, and the Wyss Institute for Biologically Inspired Engineering at Harvard University have discovered an entirely new form of biological reproduction—and applied their discovery to create the first-ever, self-replicating living robots.
The same team that built the first living robots (“Xenobots,” assembled from frog cells—reported in 2020) has discovered that these computer-designed and hand-assembled organisms can swim out into their tiny dish, find single cells, gather hundreds of them together, and assemble “baby” Xenobots inside their Pac-Man-shaped “mouth”—that, a few days later, become new Xenobots that look and move just like themselves.
And then these new Xenobots can go out, find cells, and build copies of themselves. Again and again.
In a Xenopus laevis frog, these embryonic cells would develop into skin. “They would be sitting on the outside of a tadpole, keeping out pathogens and redistributing mucus,” says Michael Levin, Ph.D., a professor of biology and director of the Allen Discovery Center at Tufts University and co-leader of the new research. “But we’re putting them into a novel context. We’re giving them a chance to reimagine their multicellularity.” Levin is also an Associate Faculty member at the Wyss Institute.
And what they imagine is something far different than skin. “People have thought for quite a long time that we’ve worked out all the ways that life can reproduce or replicate. But this is something that’s never been observed before,” says co-author Douglas Blackiston, Ph.D., the senior scientist at Tufts University and the Wyss Institute who assembled the Xenobot “parents” and developed the biological portion of the new study.
“This is profound,” says Levin. “These cells have the genome of a frog, but, freed from becoming tadpoles, they use their collective intelligence, a plasticity, to do something astounding.” In earlier experiments, the scientists were amazed that Xenobots could be designed to achieve simple tasks. Now they are stunned that these biological objects—a computer-designed collection of cells—will spontaneously replicate. “We have the full, unaltered frog genome,” says Levin, “but it gave no hint that these cells can work together on this new task,” of gathering and then compressing separated cells into working self-copies.
“These are frog cells replicating in a way that is very different from how frogs do it. No animal or plant known to science replicates in this way,” says Sam Kriegman, Ph.D., the lead author on the new study, who completed his Ph.D. in Bongard’s lab at UVM and is now a post-doctoral researcher at Tuft’s Allen Center and Harvard University’s Wyss Institute for Biologically Inspired Engineering.
Both Buckiewicz’s December 3, 2021 article and Brown’s November 29, 2021 Wyss Institute news release are good reads with liberal used of embedded images. If you have time, start with Buckiewicz as she provides a good introduction and follow up with Brown who gives more detail and has an embedded video of a December 1, 2021 panel discussion with the scientists behind the xenobots.
Here’s a link to and a citation for the latest paper,
The Canadian Broadcasting Corporation’s (CBC) science television series,The Nature of Things, which has been broadcast since November 1960, explored the world of emotional, empathic and creative artificial intelligence (AI) in a Friday, November 19, 2021 telecast titled, The Machine That Feels,
The Machine That Feels explores how artificial intelligence (AI) is catching up to us in ways once thought to be uniquely human: empathy, emotional intelligence and creativity.
As AI moves closer to replicating humans, it has the potential to reshape every aspect of our world – but most of us are unaware of what looms on the horizon.
Scientists see AI technology as an opportunity to address inequities and make a better, more connected world. But it also has the capacity to do the opposite: to stoke division and inequality and disconnect us from fellow humans. The Machine That Feels, from The Nature of Things, shows viewers what they need to know about a field that is advancing at a dizzying pace, often away from the public eye.
What does it mean when AI makes art? Can AI interpret and understand human emotions? How is it possible that AI creates sophisticated neural networks that mimic the human brain? The Machine That Feels investigates these questions, and more.
In Vienna, composer Walter Werzowa has — with the help of AI — completed Beethoven’s previously unfinished 10th symphony. By feeding data about Beethoven, his music, his style and the original scribbles on the 10th symphony into an algorithm, AI has created an entirely new piece of art.
In Atlanta, Dr. Ayanna Howard and her robotics lab at Georgia Tech are teaching robots how to interpret human emotions. Where others see problems, Howard sees opportunity: how AI can help fill gaps in education and health care systems. She believes we need a fundamental shift in how we perceive robots: let’s get humans and robots to work together to help others.
At Tufts University in Boston, a new type of biological robot has been created: the xenobot. The size of a grain of sand, xenobots are grown from frog heart and skin cells, and combined with the “mind” of a computer. Programmed with a specific task, they can move together to complete it. In the future, they could be used for environmental cleanup, digesting microplastics and targeted drug delivery (like releasing chemotherapy compounds directly into tumours).
The film includes interviews with global leaders, commentators and innovators from the AI field, including Geoff Hinton, Yoshua Bengio, Ray Kurzweil and Douglas Coupland, who highlight some of the innovative and cutting-edge AI technologies that are changing our world.
The Machine That Feels focuses on one central question: in the flourishing age of artificial intelligence, what does it mean to be human?
I’ll get back to that last bit, “… what does it mean to be human?” later.
There’s a lot to appreciate in this 44 min. programme. As you’d expect, there was a significant chunk of time devoted to research being done in the US but Poland and Japan also featured and Canadian content was substantive. A number of tricky topics were covered and transitions from one topic to the next were smooth.
In the end credits, I counted over 40 source materials from Getty Images, Google Canada, Gatebox, amongst others. It would have been interesting to find out which segments were produced by CBC.
David Suzuki’s (programme host) script was well written and his narration was enjoyable, engaging, and non-intrusive. That last quality is not always true of CBC hosts who can fall into the trap of overdramatizing the text.
I have followed artificial intelligence stories in a passive way (i.e., I don’t seek them out) for many years. Even so, there was a lot of material in the programme that was new to me.
In the The Machine That Feels, a documentary from The Nature of Things, we meet Kondo Akihiko, a Tokyo resident who “married” a hologram of virtual pop singer Hatsune Miku using a certificate issued by Gatebox (the marriage isn’t recognized by the state, and Gatebox acknowledges the union goes “beyond dimensions”).
Overall, this Nature of Things episode embraces certainty, which means the question of what it means to human is referenced rather than seriously discussed. An unanswerable philosophical question, the programme is ill-equipped to address it, especially since none of the commentators are philosophers or seem inclined to philosophize.
The programme presents AI as a juggernaut. Briefly mentioned is the notion that we need to make some decisions about how our juggernaut is developed and utilized. No one discusses how we go about making changes to systems that are already making critical decisions for us. (For more about AI and decision-making, see my February 28, 2017 posting and scroll down to the ‘Algorithms and big data’ subhead for Cathy O’Neil’s description of how important decisions that affect us are being made by AI systems. She is the author of the 2016 book, ‘Weapons of Math Destruction: How Big Data Increases Inequality and Threatens Democracy’; still a timely read.)
In fact, the programme’s tone is mostly one of breathless excitement. A few misgivings are expressed, e.g,, one woman who has an artificial ‘texting friend’ (Replika; a chatbot app) noted that it can ‘get into your head’ when she had a chat where her ‘friend’ told her that all of a woman’s worth is based on her body; she pushed back but intimated that someone more vulnerable could find that messaging difficult to deal with.
The sequence featuring Akihiko and his hologram ‘wife’ is followed by one suggesting that people might become more isolated and emotionally stunted as they interact with artificial friends. It should be noted, Akihiko’s wife is described as ‘perfect’. I gather perfection means that you are always understanding and have no needs of your own. She also seems to be about 18″ high.
Akihiko has obviously been asked about his ‘wife’ before as his answers are ready. They boil down to “there are many types of relationships” and there’s nothing wrong with that. It’s an intriguing thought which is not explored.
Also unexplored, these relationships could be said to resemble slavery. After all, you pay for these friends over which you have control. But perhaps that’s alright since AI friends don’t have consciousness. Or do they? In addition to not being able to answer the question, “what is it to be human?” we still can’t answer the question, “what is consciousness?”
AI and creativity
The Nature of Things team works fast. ‘Beethoven X – The AI Project’ had its first performance on October 9, 2021. (See my October 1, 2021 post ‘Finishing Beethoven’s unfinished 10th Symphony’ for more information from Ahmed Elgammal’s (Director of the Art & AI Lab at Rutgers University) technical perspective on the project.
Briefly, Beethoven died before completing his 10th symphony and a number of computer scientists, musicologists, AI, and musicians collaborated to finish the symphony.)
The one listener (Felix Mayer, music professor at the Technical University Munich) in the hall during a performance doesn’t consider the work to be a piece of music. He does have a point. Beethoven left some notes but this ’10th’ is at least partly mathematical guesswork. A set of probabilities where an algorithm chooses which note comes next based on probability.
There was another artist also represented in the programme. Puzzlingly, it was the still living Douglas Coupland. In my opinion, he’s better known as a visual artist than a writer (his Wikipedia entry lists him as a novelist first) but he has succeeded greatly in both fields.
What makes his inclusion in the Nature of Things ‘The Machine That Feels’ programme puzzling, is that it’s not clear how he worked with artificial intelligence in a collaborative fashion. Here’s a description of Coupland’s ‘AI’ project from a June 29, 2021 posting by Chris Henry on the Google Outreach blog (Note: Links have been removed),
… when the opportunity presented itself to explore how artificial intelligence (AI) inspires artistic expression — with the help of internationally renowned Canadian artist Douglas Coupland — the Google Research team jumped on it. This collaboration, with the support of Google Arts & Culture, culminated in a project called Slogans for the Class of 2030, which spotlights the experiences of the first generation of young people whose lives are fully intertwined with the existence of AI.
This collaboration was brought to life by first introducing Coupland’s written work to a machine learning language model. Machine learning is a form of AI that provides computer systems the ability to automatically learn from data. In this case, Google research scientists tuned a machine learning algorithm with Coupland’s 30-year body of written work — more than a million words — so it would familiarize itself with the author’s unique style of writing. From there, curated general-public social media posts on selected topics were added to teach the algorithm how to craft short-form, topical statements. [emphases mine]
Once the algorithm was trained, the next step was to process and reassemble suggestions of text for Coupland to use as inspiration to create twenty-five Slogans for the Class of 2030. [emphasis mine]
“I would comb through ‘data dumps’ where characters from one novel were speaking with those in other novels in ways that they might actually do. It felt like I was encountering a parallel universe Doug,” Coupland says. “And from these outputs, the statements you see here in this project appeared like gems. Did I write them? Yes. No. Could they have existed without me? No.” [emphases mine]
So, the algorithms crunched through Coupland’s word and social media texts to produce slogans, which Coupland then ‘combed through’ to pick out 25 slogans for the ‘Slogans For The Class of 2030’ project. (Note: In the programme, he says that he started a sentence and then the AI system completed that sentence with material gleaned from his own writings, which brings to Exquisite Corpse, a collaborative game for writers originated by the Surrealists, possibly as early as 1918.)
The ‘slogans’ project also reminds me of William S. Burroughs and the cut-up technique used in his work. From the William S. Burroughs Cut-up technique webpage on the Language is a Virus website (Thank you to Lake Rain Vajra for a very interesting website),
The cutup is a mechanical method of juxtaposition in which Burroughs literally cuts up passages of prose by himself and other writers and then pastes them back together at random. This literary version of the collage technique is also supplemented by literary use of other media. Burroughs transcribes taped cutups (several tapes spliced into each other), film cutups (montage), and mixed media experiments (results of combining tapes with television, movies, or actual events). Thus Burroughs’s use of cutups develops his juxtaposition technique to its logical conclusion as an experimental prose method, and he also makes use of all contemporary media, expanding his use of popular culture.
[Burroughs says] “All writing is in fact cut-ups. A collage of words read heard overheard. What else? Use of scissors renders the process explicit and subject to extension and variation. Clear classical prose can be composed entirely of rearranged cut-ups. Cutting and rearranging a page of written words introduces a new dimension into writing enabling the writer to turn images in cinematic variation. Images shift sense under the scissors smell images to sound sight to sound to kinesthetic. This is where Rimbaud was going with his color of vowels. And his “systematic derangement of the senses.” The place of mescaline hallucination: seeing colors tasting sounds smelling forms.
“The cut-ups can be applied to other fields than writing. Dr Neumann [emphasis mine] in his Theory of Games and Economic behavior introduces the cut-up method of random action into game and military strategy: assume that the worst has happened and act accordingly. … The cut-up method could be used to advantage in processing scientific data. [emphasis mine] How many discoveries have been made by accident? We cannot produce accidents to order. The cut-ups could add new dimension to films. Cut gambling scene in with a thousand gambling scenes all times and places. Cut back. Cut streets of the world. Cut and rearrange the word and image in films. There is no reason to accept a second-rate product when you can have the best. And the best is there for all. Poetry is for everyone . . .”
Here’s Burroughs on the history of writers and cutups (thank you to QUEDEAR for posting this clip),
You can hear Burroughs talk about the technique and how he started using it in 1959.
There is no explanation from Coupland as to how his project differs substantively from Burroughs’ cut-ups or a session of Exquisite Corpse. The use of a computer programme to crunch through data and give output doesn’t seem all that exciting. *(More about computers and chatbots at end of posting).* It’s hard to know if this was an interview situation where he wasn’t asked the question or if the editors decided against including it.
Given that Ishiguro’s 2021 book (Klara and the Sun) is focused on an artificial friend and raises the question of ‘what does it mean to be human’, as well as the related question, ‘what is the nature of consciousness’, it would have been interesting to hear from him. He spent a fair amount of time looking into research on machine learning in preparation for his book. Maybe he was too busy?
AI and emotions
The work being done by Georgia Tech’s Dr. Ayanna Howard and her robotics lab is fascinating. They are teaching robots how to interpret human emotions. The segment which features researchers teaching and interacting with robots, Pepper and Salt, also touches on AI and bias.
Watching two African American researchers talk about the ways in which AI is unable to read emotions on ‘black’ faces as accurately as ‘white’ faces is quite compelling. It also reinforces the uneasiness you might feel after the ‘Replika’ segment where an artificial friend informs a woman that her only worth is her body.
(Interestingly, Pepper and Salt are produced by Softbank Robotics, part of Softbank, a multinational Japanese conglomerate, [see a June 28, 2021 article by Ian Carlos Campbell for The Verge] whose entire management team is male according to their About page.)
While Howard is very hopeful about the possibilities of a machine that can read emotions, she doesn’t explore (on camera) any means for pushing back against bias other than training AI by using more black faces to help them learn. Perhaps more representative management and coding teams in technology companies?
While the programme largely focused on AI as an algorithm on a computer, robots can be enabled by AI (as can be seen in the segment with Dr. Howard).
“I’ve always felt that robots shouldn’t just be modeled after humans [emphasis mine] or be copies of humans,” he [Guy Hoffman, assistant professor at Cornell University)] said. “We have a lot of interesting relationships with other species. Robots could be thought of as one of those ‘other species,’ not trying to copy what we do but interacting with us with their own language, tapping into our own instincts.”
This brings the question back to, what is consciousness?
What scientists aren’t taught
Dr. Howard notes that scientists are not taught to consider the implications of their work. Her comment reminded me of a question I was asked many years ago after a presentation, it concerned whether or not science had any morality. (I said, no.)
My reply angered an audience member (a visual artist who was working with scientists at the time) as she took it personally and started defending scientists as good people who care and have morals and values. She failed to understand that the way in which we teach science conforms to a notion that somewhere there are scientific facts which are neutral and objective. Society and its values are irrelevant in the face of the larger ‘scientific truth’ and, as a consequence, you don’t need to teach or discuss how your values or morals affect that truth or what the social implications of your work might be.
Science is practiced without much if any thought to values. By contrast, there is the medical injunction, “Do no harm,” which suggests to me that someone recognized competing values. E.g., If your important and worthwhile research is harming people, you should ‘do no harm’.
The experts, the connections, and the Canadian content
It’s been a while since I’ve seen Ray Kurzweil mentioned but he seems to be getting more attention these days. (See this November 16, 2021 posting by Jonny Thomson titled, “The Singularity: When will we all become super-humans? Are we really only a moment away from “The Singularity,” a technological epoch that will usher in a new era in human evolution?” on The Big Think for more). Note: I will have a little more about evolution later in this post.
Interestingly, Kurzweil is employed by Google these days (see his Wikipedia entry, the column to the right). So is Geoffrey Hinton, another one of the experts in the programme (see Hinton’s Wikipedia entry, the column to the right, under Institutions).
I’m not sure about Yoshu Bengio’s relationship with Google but he’s a professor at the Université de Montréal, and he’s the Scientific Director for Mila ((Quebec’s Artificial Intelligence research institute)) & IVADO (Institut de valorisation des données), Note: IVADO is not particularly relevant to what’s being discussed in this post.
Google invests $4.5 Million in Montreal AI Research
A new grant from Google for the Montreal Institute for Learning Algorithms (MILA) will fund seven faculty across a number of Montreal institutions and will help tackle some of the biggest challenges in machine learning and AI, including applications in the realm of systems that can understand and generate natural language. In other words, better understand a fan’s enthusiasm for Les Canadien [sic].
Google is expanding its academic support of deep learning at MILA, renewing Yoshua Bengio’s Focused Research Award and offering Focused Research Awards to MILA faculty at University of Montreal and McGill University:
Google reaffirmed their commitment to Mila in 2020 with a grant worth almost $4M (from a November 13, 2020 posting on the Mila website, Note: A link has been removed),
Google Canada announced today [November 13, 2020] that it will be renewing its funding of Mila – Quebec Artificial Intelligence Institute, with a generous pledge of nearly $4M over a three-year period. Google previously invested $4.5M US in 2016, enabling Mila to grow from 25 to 519 researchers.
In a piece written for Google’s Official Canada Blog, Yoshua Bengio, Mila Scientific Director, says that this year marked a “watershed moment for the Canadian AI community,” as the COVID-19 pandemic created unprecedented challenges that demanded rapid innovation and increased interdisciplinary collaboration between researchers in Canada and around the world.
“COVID-19 has changed the world forever and many industries, from healthcare to retail, will need to adapt to thrive in our ‘new normal.’ As we look to the future and how priorities will shift, it is clear that AI is no longer an emerging technology but a useful tool that can serve to solve world problems. Google Canada recognizes not only this opportunity but the important task at hand and I’m thrilled they have reconfirmed their support of Mila with an additional $3,95 million funding grant until 22.“
– Yoshua Bengio, for Google’s Official Canada Blog
Interesting, eh? Of course, Douglas Coupland is working with Google, presumably for money, and that would connect over 50% of the Canadian content (Douglas Coupland, Yoshua Bengio, and Geoffrey Hinton; Kurzweil is an American) in the programme to Google.
My hat’s off to Google’s marketing communications and public relations teams.
Anthony Morgan of Science Everywhere also provided some Canadian content. His LinkedIn profile indicates that he’s working on a PhD in molecular science, which is described this way, “My work explores the characteristics of learning environments, that support critical thinking and the relationship between critical thinking and wisdom.”
Morgan is also the founder and creative director of Science Everywhere, from his LinkedIn profile, “An events & media company supporting knowledge mobilization, community engagement, entrepreneurship and critical thinking. We build social tools for better thinking.”
There is this from his LinkedIn profile,
I develop, create and host engaging live experiences & media to foster critical thinking.
I’ve spent my 15+ years studying and working in psychology and science communication, thinking deeply about the most common individual and societal barriers to critical thinking. As an entrepreneur, I lead a team to create, develop and deploy cultural tools designed to address those barriers. As a researcher I study what we can do to reduce polarization around science.
There’s a lot more to Morgan (do look him up; he has connections to the CBC and other media outlets). The difficulty is: why was he chosen to talk about artificial intelligence and emotions and creativity when he doesn’t seem to know much about the topic? He does mention GPT-3, an AI programming language. He seems to be acting as an advocate for AI although he offers this bit of almost cautionary wisdom, “… algorithms are sets of instructions.” (You can can find out more about it in my April 27, 2021 posting. There’s also this November 26, 2021 posting [The Inherent Limitations of GPT-3] by Andrey Kurenkov, a PhD student with the Stanford [University] Vision and Learning Lab.)
Most of the cautionary commentary comes from Luke Stark, assistant professor at Western [Ontario] University’s Faculty of Information and Media Studies. He’s the one who mentions stunted emotional growth.
Before moving on, there is another set of connections through the Pan-Canadian Artificial Intelligence Strategy, a Canadian government science funding initiative announced in the 2017 federal budget. The funds allocated to the strategy are administered by the Canadian Institute for Advanced Research (CIFAR). Yoshua Bengio through Mila is associated with the strategy and CIFAR, as is Geoffrey Hinton through his position as Chief Scientific Advisor for the Vector Institute.
Getting back to “The Singularity: When will we all become super-humans? Are we really only a moment away from “The Singularity,” a technological epoch that will usher in a new era in human evolution?” Xenobots point in a disconcerting (for some of us) evolutionary direction.
I featured the work, which is being done at Tufts University in the US, in my June 21, 2021 posting, which includes an embedded video,
Last year, a team of biologists and computer scientists from Tufts University and the University of Vermont (UVM) created novel, tiny self-healing biological machines from frog cells called “Xenobots” that could move around, push a payload, and even exhibit collective behavior in the presence of a swarm of other Xenobots.
Get ready for Xenobots 2.0.
Also from an excerpt in the posting, the team has “created life forms that self-assemble a body from single cells, do not require muscle cells to move, and even demonstrate the capability of recordable memory.”
Memory is key to intelligence and this work introduces the notion of ‘living’ robots which leads to questioning what constitutes life. ‘The Machine That Feels’ is already grappling with far too many questions to address this development but introducing the research here might have laid the groundwork for the next episode, The New Human, telecast on November 26, 2021,
While no one can be certain what will happen, evolutionary biologists and statisticians are observing trends that could mean our future feet only have four toes (so long, pinky toe) or our faces may have new combinations of features. The new humans might be much taller than their parents or grandparents, or have darker hair and eyes.
And while evolution takes a lot of time, we might not have to wait too long for a new version of ourselves.
Technology is redesigning the way we look and function — at a much faster pace than evolution. We are merging with technology more than ever before: our bodies may now have implanted chips, smart limbs, exoskeletons and 3D-printed organs. A revolutionary gene editing technique has given us the power to take evolution into our own hands and alter our own DNA. How long will it be before we are designing our children?
As the story about the xenobots doesn’t say, we could also take the evolution of another species into our hands.
David Suzuki, where are you?
Our programme host, David Suzuki surprised me. I thought that as an environmentalist he’d point out that the huge amounts of computing power needed for artificial intelligence as mentioned in the programme, constitutes an environmental issue. I also would have expected a geneticist like Suzuki might have some concerns with regard to xenobots but perhaps that’s being saved for the next episode (The New Human) of the Nature of Things.
Thanks to Will Knight for introducing me to the term ‘artificial stupidity’. Knight, a senior writer covers artificial intelligence for WIRED magazine. According to its Wikipedia entry,
Artificial stupidity is commonly used as a humorous opposite of the term artificial intelligence (AI), often as a derogatory reference to the inability of AI technology to adequately perform its tasks. However, within the field of computer science, artificial stupidity is also used to refer to a technique of “dumbing down” computer programs in order to deliberately introduce errors in their responses.
Knight was using the term in its humorous, derogatory form.
The episode certainly got me thinking if not quite in the way producers might have hoped. ‘The Machine That Feels’ is a glossy, pretty well researched piece of infotainment.
To be blunt, I like and have no problems with infotainment but it can be seductive. I found it easier to remember the artificial friends, wife, xenobots, and symphony than the critiques and concerns.
Hopefully, ‘The Machine That Feels’ stimulates more interest in some very important topics. If you missed the telecast, you can catch the episode here.
For anyone curious about predictive policing, which was mentioned in the Ayanna Howard segment, see my November 23, 2017 posting about Vancouver’s plunge into AI and car theft.
*ETA December 6, 2021: One of the first ‘chatterbots’ was ELIZA, a computer programme developed from1964 to 1966. The most famous ELIZA script was DOCTOR, where the programme simulated a therapist. Many early users believed ELIZA understood and could respond as a human would despite Joseph Weizenbaum’s (creator of the programme) insistence otherwise.
I meant to feature this work last year when it was first announced so I’m delighted a second chance has come around so soon after. From a March 31, 2021 news item on ScienceDaily,
Last year, a team of biologists and computer scientists from Tufts University and the University of Vermont (UVM) created novel, tiny self-healing biological machines from frog cells called “Xenobots” that could move around, push a payload, and even exhibit collective behavior in the presence of a swarm of other Xenobots.
Get ready for Xenobots 2.0.
Here’s a video of the Xenobot 2.0. It’s amazing but, for anyone who has problems with animal experimentation, this may be disturbing,
The next version of Xenobots have been created – they’re faster, live longer, and can now record information. (Source: Doug Blackiston & Emma Lederer)
The same team has now created life forms that self-assemble a body from single cells, do not require muscle cells to move, and even demonstrate the capability of recordable memory. The new generation Xenobots also move faster, navigate different environments, and have longer lifespans than the first edition, and they still have the ability to work together in groups and heal themselves if damaged. The results of the new research were published today [March 31, 2021] in Science Robotics.
Compared to Xenobots 1.0, in which the millimeter-sized automatons were constructed in a “top down” approach by manual placement of tissue and surgical shaping of frog skin and cardiac cells to produce motion, the next version of Xenobots takes a “bottom up” approach. The biologists at Tufts took stem cells from embryos of the African frog Xenopus laevis (hence the name “Xenobots”) and allowed them to self-assemble and grow into spheroids, where some of the cells after a few days differentiated to produce cilia – tiny hair-like projections that move back and forth or rotate in a specific way. Instead of using manually sculpted cardiac cells whose natural rhythmic contractions allowed the original Xenobots to scuttle around, cilia give the new spheroidal bots “legs” to move them rapidly across a surface. In a frog, or human for that matter, cilia would normally be found on mucous surfaces, like in the lungs, to help push out pathogens and other foreign material. On the Xenobots, they are repurposed to provide rapid locomotion.
“We are witnessing the remarkable plasticity of cellular collectives, which build a rudimentary new ‘body’ that is quite distinct from their default – in this case, a frog – despite having a completely normal genome,” said Michael Levin, Distinguished Professor of Biology and director of the Allen Discovery Center at Tufts University, and corresponding author of the study. “In a frog embryo, cells cooperate to create a tadpole. Here, removed from that context, we see that cells can re-purpose their genetically encoded hardware, like cilia, for new functions such as locomotion. It is amazing that cells can spontaneously take on new roles and create new body plans and behaviors without long periods of evolutionary selection for those features.”
“In a way, the Xenobots are constructed much like a traditional robot. Only we use cells and tissues rather than artificial components to build the shape and create predictable behavior.” said senior scientist Doug Blackiston, who co-first authored the study with research technician Emma Lederer. “On the biology end, this approach is helping us understand how cells communicate as they interact with one another during development, and how we might better control those interactions.”
While the Tufts scientists created the physical organisms, scientists at UVM were busy running computer simulations that modeled different shapes of the Xenobots to see if they might exhibit different behaviors, both individually and in groups. Using the Deep Green supercomputer cluster at UVM’s Vermont Advanced Computing Core, the team, led by computer scientists and robotics experts Josh Bongard and Sam Kriegman, simulated the Xenbots under hundreds of thousands of random environmental conditions using an evolutionary algorithm. These simulations were used to identify Xenobots most able to work together in swarms to gather large piles of debris in a field of particles
“We know the task, but it’s not at all obvious — for people — what a successful design should look like. That’s where the supercomputer comes in and searches over the space of all possible Xenobot swarms to find the swarm that does the job best,” says Bongard. “We want Xenobots to do useful work. Right now we’re giving them simple tasks, but ultimately we’re aiming for a new kind of living tool that could, for example, clean up microplastics in the ocean or contaminants in soil.”
It turns out, the new Xenobots are much faster and better at tasks such as garbage collection than last year’s model, working together in a swarm to sweep through a petri dish and gather larger piles of iron oxide particles. They can also cover large flat surfaces, or travel through narrow capillary tubes.
These studies also suggest that the in silico [computer] simulations could in the future optimize additional features of biological bots for more complex behaviors. One important feature added in the Xenobot upgrade is the ability to record information.
Now with memory
A central feature of robotics is the ability to record memory and use that information to modify the robot’s actions and behavior. With that in mind, the Tufts scientists engineered the Xenobots with a read/write capability to record one bit of information, using a fluorescent reporter protein called EosFP, which normally glows green. However, when exposed to light at 390nm wavelength, the protein emits red light instead.
The cells of the frog embryos were injected with messenger RNA coding for the EosFP protein before stem cells were excised to create the Xenobots. The mature Xenobots now have a built-in fluorescent switch which can record exposure to blue light around 390nm. The researchers tested the memory function by allowing 10 Xenobots to swim around a surface on which one spot is illuminated with a beam of 390nm light. After two hours, they found that three bots emitted red light. The rest remained their original green, effectively recording the “travel experience” of the bots.
This proof of principle of molecular memory could be extended in the future to detect and record not only light but also the presence of radioactive contamination, chemical pollutants, drugs, or a disease condition. Further engineering of the memory function could enable the recording of multiple stimuli (more bits of information) or allow the bots to release compounds or change behavior upon sensation of stimuli.
“When we bring in more capabilities to the bots, we can use the computer simulations to design them with more complex behaviors and the ability to carry out more elaborate tasks,” said Bongard. “We could potentially design them not only to report conditions in their environment but also to modify and repair conditions in their environment.”
Xenobot, heal thyself
“The biological materials we are using have many features we would like to someday implement in the bots – cells can act like sensors, motors for movement, communication and computation networks, and recording devices to store information,” said Levin. “One thing the Xenobots and future versions of biological bots can do that their metal and plastic counterparts have difficulty doing is constructing their own body plan as the cells grow and mature, and then repairing and restoring themselves if they become damaged. Healing is a natural feature of living organisms, and it is preserved in Xenobot biology.”
The new Xenobots were remarkably adept at healing and would close the majority of a severe full-length laceration half their thickness within 5 minutes of the injury. All injured bots were able to ultimately heal the wound, restore their shape and continue their work as before.
Another advantage of a biological robot, Levin adds, is metabolism. Unlike metal and plastic robots, the cells in a biological robot can absorb and break down chemicals and work like tiny factories synthesizing and excreting chemicals and proteins. The whole field of synthetic biology – which has largely focused on reprogramming single celled organisms to produce useful molecules – can now be exploited in these multicellular creatures
Like the original Xenobots, the upgraded bots can survive up to ten days on their embryonic energy stores and run their tasks without additional energy sources, but they can also carry on at full speed for many months if kept in a “soup” of nutrients.
What the scientists are really after
An engaging description of the biological bots and what we can learn from them is presented in a TED talk by Michael Levin. In his TED Talk, professor Levin describes not only the remarkable potential for tiny biological robots to carry out useful tasks in the environment or potentially in therapeutic applications, but he also points out what may be the most valuable benefit of this research – using the bots to understand how individual cells come together, communicate, and specialize to create a larger organism, as they do in nature to create a frog or human. It’s a new model system that can provide a foundation for regenerative medicine.
Xenobots and their successors may also provide insight into how multicellular organisms arose from ancient single celled organisms, and the origins of information processing, decision making and cognition in biological organisms.
Recognizing the tremendous future for this technology, Tufts University and the University of Vermont have established the Institute for Computer Designed Organisms (ICDO), to be formally launched in the coming months, which will pull together resources from each university and outside sources to create living robots with increasingly sophisticated capabilities.
The ultimate goal for the Tufts and UVM researchers is not only to explore the full scope of biological robots they can make; it is also to understand the relationship between the ‘hardware’ of the genome and the ‘software’ of cellular communications that go into creating organized tissues, organs and limbs. Then we can gain greater control of that morphogenesis for regenerative medicine, and the treatment of cancer and diseases of aging.
Apparently the magic is in the lipid nanoparticles. A March 1, 2021 news item on Nanowerk announced research into lipid nanoparticles as a means to deliver CRISPR (clustered regularly interspaced short palindromic repeats) to specific organs (Note: A link has been removed),
The genome editing technology CRISPR has emerged as a powerful new tool that can change the way we treat disease. The challenge when altering the genetics of our cells, however, is how to do it safely, effectively, and specifically targeted to the gene, tissue and organ that needs treatment.
Scientists at Tufts University and the Broad Institute of Harvard [University] and MIT [Massachusetts Institute of Technology] have developed unique nanoparticles comprised of lipids — fat molecules — that can package and deliver gene editing machinery specifically to the liver.
In a study published in the Proceedings of the National Academy of Sciences [PNAS] (“Lipid nanoparticle-mediated codelivery of Cas9 mRNA and single-guide RNA achieves liver-specific in vivo genome editing of Angptl3”), they have shown that they can use the lipid nanoparticles (LNPs) to efficiently deliver the CRISPR machinery into the liver of mice, resulting in specific genome editing and the reduction of blood cholesterol levels by as much as 57% — a reduction that can last for at least several months with just one shot.
The problem of high cholesterol plagues more than 29 million Americans, according to the Centers for Disease Control and Prevention. The condition is complex and can originate from multiple genes as well as nutritional and lifestyle choices, so it is not easy to treat. The Tufts and Broad researchers, however, have modified one gene that could provide a protective effect against elevated cholesterol if it can be shut down by gene editing.
The gene that the researchers focused on codes for the angiopoietin-like 3 enzyme (Angptl3). That enzyme tamps down the activity of other enzymes – lipases – that help break down cholesterol. If researchers can knock out the Angptl3 gene, they can let the lipases do their work and reduce levels of cholesterol in the blood. It turns out that some lucky people have a natural mutation in their Angptl3 gene, leading to consistently low levels of triglycerides and low-density lipoprotein (LDL) cholesterol, commonly called “bad” cholesterol, in their bloodstream without any known clinical downsides.
“If we can replicate that condition by knocking out the angptl3 gene in others, we have a good chance of having a safe and long term solution to high cholesterol,” said Qiaobing Xu, associate professor of biomedical engineering at Tufts’ School of Engineering and corresponding author of the study. “We just have to make sure we deliver the gene editing package specifically to the liver so as not to create unwanted side effects.”
Xu’s team was able to do precisely that in mouse models. After a single injection of lipid nanoparticles packed with mRNA coding for CRISPR-Cas9 and a single-guide RNA targeting Angptl3, they observed a profound reduction in LDL cholesterol by as much as 57% and triglyceride levels by about 29 %, both of which remained at those lowered levels for at least 100 days. The researchers speculate that the effect may last much longer than that, perhaps limited only by the slow turnover of cells in the liver, which can occur over a period of about a year. The reduction of cholesterol and triglycerides is dose dependent, so their levels could be adjusted by injecting fewer or more LNPs in the single shot, the researchers said.
By comparison, an existing, FDA [US Food and Drug Administration]-approved version of CRISPR mRNA-loaded LNPs could only reduce LDL cholesterol by at most 15.7% and triglycerides by 16.3% when it was tested in mice, according to the researchers.
The trick to making a better LNP was in customizing the components – the molecules that come together to form bubbles around the mRNA. The LNPs are made up of long chain lipids that have a charged or polar head that is attracted to water, a carbon chain tail that points toward the middle of the bubble containing the payload, and a chemical linker between them. Also present are polyethylene glycol, and yes, even some cholesterol – which has a normal role in lipid membranes to make them less leaky – to hold their contents better.
The researchers found that the nature and relative ratio of these components appeared to have profound effects on the delivery of mRNA into the liver, so they tested LNPs with many combinations of heads, tails, linkers and ratios among all components for their ability to target liver cells. Because the in vitro potency of an LNP formulation rarely reflects its in vivo performance, they directly evaluated the delivery specificity and efficacy in mice that have a reporter gene in their cells that lights up red when genome editing occurs. Ultimately, they found a CRISPR mRNA-loaded LNP that lit up just the liver in mice, showing that it could specifically and efficiently deliver gene-editing tools into the liver to do their work.
The LNPs were built upon earlier work at Tufts, where Xu and his team developed LNPs with as much as 90% efficiency in delivering mRNA into cells. A unique feature of those nanoparticles was the presence of disulfide bonds between the long lipid chains. Outside the cells, the LNPs form a stable spherical structure that locks in their contents. When they are inside a cell, the environment within breaks the disulfide bonds to disassemble the nanoparticles. The contents are then quickly and efficiently released into the cell. By preventing loss outside the cell, the LNPs can have a much higher yield in delivering their contents.
“CRISPR is one of the most powerful therapeutic tools for the treatment of diseases with a genetic etiology. We have recently seen the first human clinical trail for CRISPR therapy enabled by LNP delivery to be administered systemically to edit genes inside the human body. Our LNP platform developed here holds great potential for clinical translation,” said Min Qiu, post-doctoral researcher in Xu’s lab at Tufts. “We envision that with this LNP platform in hand, we could now make CRISPR a practical and safe approach to treat a broad spectrum of liver diseases or disorders,” said Zachary Glass, graduate student in the Xu lab. Qiu and Glass are co-first authors of the study.
In fact, I have two items about fungi and I’m starting with the essay first.
Giving thanks for fungi
Antonis Rokas, professor at Venderbilt University (Nashville, Tennessee, US), has written a November 25, 2019 essay for The Conversation (h/t phys.org Nov.26.19) featuring fungi and food, Note: Links have been removed),
I am an evolutionary biologist studying fungi, a group of microbes whose domestication has given us many tasty products. I’ve long been fascinated by two questions: What are the genetic changes that led to their domestication? And how on Earth did our ancestors figure out how to domesticate them?
The hybrids in your lager
As far as domestication is concerned, it is hard to top the honing of brewer’s yeast. The cornerstone of the baking, brewing and wine-making industries, brewer’s yeast has the remarkable ability to turn the sugars of plant fruits and grains into alcohol. How did brewer’s yeast evolve this flexibility?
By discovering new yeast species and sequencing their genomes, scientists know that some yeasts used in brewing are hybrids; that is, they’re descendants of ancient mating unions of individuals from two different yeast species. Hybrids tend to resemble both parental species – think of wholpins (whale-dolphin) or ligers (lion-tiger).
… What is still unknown is whether hybridization is the norm or the exception in the yeasts that humans have used for making fermented beverages for millennia.
To address this question, a team led by graduate student Quinn Langdon at the University of Wisconsin and another team led by postdoctoral fellow Brigida Gallone at the Universities of Ghent and Leuven in Belgium examined the genomes of hundreds of yeasts involved in brewing and wine making. Their bottom line? Hybrids rule.
For example, a quarter of yeasts collected from industrial environments, including beer and wine manufacturers, are hybrids.
The mutants in your cheese
Comparing the genomes of domesticated fungi to their wild relatives helps scientists understand the genetic changes that gave rise to some favorite foods and drinks. But how did our ancestors actually domesticate these wild fungi? None of us was there to witness how it all started. To solve this mystery, scientists are experimenting with wild fungi to see if they can evolve into organisms resembling those that we use to make our food today.
Benjamin Wolfe, a microbiologist at Tufts University, and his team addressed this question by taking wild Penicillium mold and growing the samples for one month in his lab on a substance that included cheese. That may sound like a short period for people, but it is one that spans many generations for fungi.
The wild fungi are very closely related to fungal strains used by the cheese industry in the making of Camembert cheese, but look very different from them. For example, wild strains are green and smell, well, moldy compared to the white and odorless industrial strains.
For Wolfe, the big question was whether he could experimentally recreate, and to what degree, the process of domestication. What did the wild strains look and smell like after a month of growth on cheese? Remarkably, what he and his team found was that, at the end of the experiment, the wild strains looked much more similar to known industrial strains than to their wild ancestor. For example, they were white in color and smelled much less moldy.
… how did the wild strain turn into a domesticated version? Did it mutate? By sequencing the genomes of both the wild ancestors and the domesticated descendants, and measuring the activity of the genes while growing on cheese, Wolfe’s team figured out that these changes did not happen through mutations in the organisms’ genomes. Rather, they most likely occurred through chemical alterations that modify the activity of specific genes but don’t actually change the genetic code. Such so-called epigenetic modifications can occur much faster than mutations.
Fantastic Fungi Futures (FFF) Nov. 29, Dec. 1, and Dec. 4, 2019 events in Toronto, Canada
The ArtSci Salon emailed me a November 23, 2019 announcement about a special series being presented in partnership with the Mycological Society of Toronto (MST) on the topic of fungi,
Fantastic Fungi Futures a discussion, a mini exhibition, a special screening, and a workshop revolving around Fungi and their versatile nature.
NOV 29 , 6:00-8:00 PM Fantastic Fungi Futures (FFF): a roundtable discussion and popup exhibition.
Join us for a roundtable discussion. what are the potentials of fungi? Our guests will share their research, as well as professional and artistic practice dealing with the taxonomy and the toxicology, the health benefits and the potentials for sustainability, as well as the artistic and architectural virtues of fungi and mushrooms. The Exhibition will feature photos and objects created by local and Canadian artists who have been working with mushrooms and fungi.
This discussion is in anticipation of the special screening of Fantastic Fungi at the HotDocs Cinema on Dec 1  our guests:James Scott,Occupational & Environmental Health, Dalla Lana School of Public Health, UofT; Marshall Tyler, Director of Research, Field Trip, Toronto; Rotem Petranker, PhD student, Social Psychology, York University; Nourin Aman, PhD student, fungal biology and Systematics lab, Punjab University; Sydney Gram, PhD student, Ecology & Evolutionary Biology student researcher (UofT/ROM); [and] Tosca Teran, Interdisciplinary artist.
DEC. 4 , 7:00-10:00PM Multi-species entanglements:Sculpting with Mycelium, @InterAccess, 950 Dupont St., Unit 1
This workshop is a continuation of ArtSci Salon’s Fantastic Fungi Futures event and the HotDocs screening of Fantastic Fungi.this workshop is open to public to attend, however, pre-registration is required. $5.00 to form a mycelium bowl to take home.
During this workshop Tosca Teran introduces the amazing potential of Mycelium for collaboration at the intersection of art and science. Participants learn how to transform their kitchens and closets in to safe, mini-Mycelium biolabs and have the option to leave the workshop with a live Mycelium planter/bowl form, as well as a wide array of possibilities of how they might work with this sustainable bio-material.
Nourin Aman is a PhD student at fungal biology and Systematics lab at Punjab University, Lahore, Pakistan. She is currently a visiting PhD student at the Mycology lab, Royal Ontario Museum. Her research revolves around comparison between macrofungal biodiversity of some reserve forests of Punjab, Pakistan.Her interest is basically to enlist all possible macrofungi of reserve forests under study and describe new species as well from area as our part of world still has many species to be discovered and named. She will be discussing factors which are affecting the fungal biodiversity in these reserve forests.
Sydney Gram is an Ecology & Evolutionary Biology student researcher (UofT/ROM)
Rotem Petranker- Bsc in psychology from the University of Toronto and a MA in social psychology from York University. Rotem is currently a PhD student in York’s clinical psychology program. His main research interest is affect regulation, and the way it interacts with sustained attention, mind wandering, and creativity. Rotem is a founding member oft the Psychedelic Studies Research Program at the University of Toronto, has published work on microdosing, and presented original research findings on psychedelic research in several conferences. He feels strongly that the principles of Open Science are necessary in order to do good research, and is currently in the process of starting the first lab study of microdosing in Canada.
Marshall Tyler– Director of Research, Field Trip. Marshall is a scientist with a deep interest in psychoactive molecules. His passion lies in guiding research to arrive at a deeper understanding of consciousness with the ultimate goal of enhancing wellbeing. At Field Trip, he is helping to develop a lab in Jamaica to explore the chemical and biological complexities of psychoactive fungi.
Tosca Teran, aka Nanotopia, is an Multi-disciplinary artist. Her work has been featured at SOFA New York, Culture Canada, and The Toronto Design Exchange. Tosca has been awarded artist residencies with The Ayatana Research Program in Ottawa and The Icelandic Visual Artists Association through Sím, Reykjavik Iceland and Nes artist residency in Skagaströnd, Iceland. In 2019 she was one of the first Bio-Artists in residence at the Museum of Contemporary Art Toronto in partnership with the Ontario Science Centre as part of the Alien Agencies Collective. A recipient of the 2019 BigCi Environmental Award at Wollemi National Park within the UNESCO World Heritage site in the Greater Blue Mountains. Tosca started collaborating artistically with Algae, Physarum polycephalum, and Mycelium in 2016, translating biodata from non-human organisms into music.@MothAntler @nanopodstudio www.toscateran.com www.nanotopia.net8
A new material based on silk proteins has been developed at Tufts University (US), according to a Dec. 26, 2016 news item on ScienceDaily,
Tufts University engineers have created a new format of solids made from silk protein that can be preprogrammed with biological, chemical, or optical functions, such as mechanical components that change color with strain, deliver drugs, or respond to light, according to a paper published online this week [Dec. 26 -30, 2016] in Proceedings of the National Academy of Sciences (PNAS).
Caption: This image shows examples of engineered 3-D silk constructs. Credit: Silklab, Department of Biomedical Engineering, School of Engineering, Tufts University
Using a water-based fabrication method based on protein self-assembly, the researchers generated three-dimensional bulk materials out of silk fibroin, the protein that gives silk its durability. Then they manipulated the bulk materials with water-soluble molecules to create multiple solid forms, from the nano- to the micro-scale, that have embedded, pre-designed functions.
For example, the researchers created a surgical pin that changes color as it nears its mechanical limits and is about to fail, functional screws that can be heated on demand in response to infrared light, and a biocompatible component that enables the sustained release of bioactive agents, such as enzymes.
Although more research is needed, additional applications could include new mechanical components for orthopedics that can be embedded with growth factors or enzymes, a surgical screw that changes color as it reaches its torque limits, hardware such as nuts and bolts that sense and report on the environmental conditions of their surroundings, or household goods that can be remolded or reshaped.
Silk’s unique crystalline structure makes it one of nature’s toughest materials. Fibroin, an insoluble protein found in silk, has a remarkable ability to protect other materials while being fully biocompatible and biodegradable.
Are sutures which gather data hackable? It’s a little early to start thinking about that issue as this seems to be brand new research. A July 18, 2016 news item on ScienceDaily tells more,
For the first time, researchers led by Tufts University engineers have integrated nano-scale sensors, electronics and microfluidics into threads — ranging from simple cotton to sophisticated synthetics — that can be sutured through multiple layers of tissue to gather diagnostic data wirelessly in real time, according to a paper published online July 18  in Microsystems & Nanoengineering. The research suggests that the thread-based diagnostic platform could be an effective substrate for a new generation of implantable diagnostic devices and smart wearable systems.
The researchers used a variety of conductive threads that were dipped in physical and chemical sensing compounds and connected to wireless electronic circuitry to create a flexible platform that they sutured into tissue in rats as well as in vitro. The threads collected data on tissue health (e.g. pressure, stress, strain and temperature), pH and glucose levels that can be used to determine such things as how a wound is healing, whether infection is emerging, or whether the body’s chemistry is out of balance. The results were transmitted wirelessly to a cell phone and computer.
The three-dimensional platform is able to conform to complex structures such as organs, wounds or orthopedic implants.
While more study is needed in a number of areas, including investigation of long-term biocompatibility, researchers said initial results raise the possibility of optimizing patient-specific treatments.
“The ability to suture a thread-based diagnostic device intimately in a tissue or organ environment in three dimensions adds a unique feature that is not available with other flexible diagnostic platforms,” said Sameer Sonkusale, Ph.D., corresponding author on the paper and director of the interdisciplinary Nano Lab in the Department of Electrical and Computer Engineering at Tufts School of Engineering. “We think thread-based devices could potentially be used as smart sutures for surgical implants, smart bandages to monitor wound healing, or integrated with textile or fabric as personalized health monitors and point-of-care diagnostics.”
Until now, the structure of substrates for implantable devices has essentially been two-dimensional, limiting their usefulness to flat tissue such as skin, according to the paper. Additionally, the materials in those substrates are expensive and require specialized processing.
Half of the world’s fruit and vegetable crops are lost during the food supply chain, due mostly to premature deterioration of these perishable foods, according to the Food and Agriculture Organization (FAO) of the United Nations.
Tufts University biomedical engineers have demonstrated that fruits can stay fresh for more than a week without refrigeration if they are coated in an odorless, biocompatible silk solution so thin as to be virtually invisible. The approach is a promising alternative for preservation of delicate foods using a naturally derived material and a water-based manufacturing process.
Silk’s unique crystalline structure makes it one of nature’s toughest materials. Fibroin, an insoluble protein found in silk, has a remarkable ability to stabilize and protect other materials while being fully biocompatible and biodegradable.
For the study, researchers dipped freshly picked strawberries in a solution of 1 percent silk fibroin protein; the coating process was repeated up to four times. The silk fibroin-coated fruits were then treated for varying amounts of time with water vapor under vacuum (water annealed) to create varying percentages of crystalline beta-sheets in the coating. The longer the exposure, the higher the percentage of beta-sheets and the more robust the fibroin coating. The coating was 27 to 35 microns thick.
The strawberries were then stored at room temperature. Uncoated berries were compared over time with berries dipped in varying numbers of coats of silk that had been annealed for different periods of time. At seven days, the berries coated with the higher beta-sheet silk were still juicy and firm while the uncoated berries were dehydrated and discolored.
Tests showed that the silk coating prolonged the freshness of the fruits by slowing fruit respiration, extending fruit firmness and preventing decay.
“The beta-sheet content of the edible silk fibroin coatings made the strawberries less permeable to carbon dioxide and oxygen. We saw a statistically significant delay in the decay of the fruit,” said senior and corresponding study author Fiorenzo G. Omenetto, Ph.D. Omenetto is the Frank C. Doble Professor in the Department of Biomedical Engineering and also has appointments in the Department of Electrical Engineering and in the Department of Physics in the School of Arts and Sciences.
Similar experiments were performed on bananas, which, unlike strawberries, are able to ripen after they are harvested. The silk coating decreased the bananas’ ripening rate compared with uncoated controls and added firmness to the fruit by preventing softening of the peel.
The thin, odorless silk coating did not affect fruit texture. Taste was not studied.
“Various therapeutic agents could be easily added to the water-based silk solution used for the coatings, so we could potentially both preserve and add therapeutic function to consumable goods without the need for complex chemistries,” said the study’s first author, Benedetto Marelli, Ph.D., formerly a post-doctoral associate in the Omenetto laboratory and now at MIT.
There’s something mind boggling to me about the notion of a single atom catalyst. Luckily, an Oct. 5, 2015 news item on Nanowerk describes the research (Note: A link has been removed),
A new generation of platinum-copper catalysts that require very low concentrations of platinum in the form of individual atoms to cleanly and cheaply perform important chemical reactions is reported today by Tufts University researchers in the journal Nature Communications (“Selective hydrogenation of butadiene on platinum copper alloys at the single atom limit”).
Platinum is used as a catalyst in fuel cells, in automobile converters and in the chemical industry because of its remarkable ability to facilitate a wide range of chemical reactions. However, its future potential uses are significantly limited by scarcity and cost, as well as the fact that platinum readily binds with carbon monoxide, which “poisons” the desired reactions, for example in polymer electrolyte membrane (PEM) fuel cells, which are the leading contenders for small-scale and mobile power generation not based on batteries or combustion engines.
The Tufts researchers discovered that dispersing individual, isolated platinum atoms in much less costly copper surfaces can create a highly effective and cost-efficient catalyst for the selective hydrogenation of 1,3 butadiene, a chemical produced by steam cracking of naphtha or by catalytic cracking of gas oil. Butadiene is an impurity in propene streams that must be removed from the stream through hydrogenation in order to facilitate downstream polymer production. The current industrial catalyst for butadiene hydrogenation uses palladium and silver.
Like Sugar in Coffee
Copper, while a relatively cheap metal, is not nearly as catalytically powerful as platinum, noted Professor of Chemistry Charles Sykes, Ph.D., one of the senior authors on the paper. “We wanted to find a way to improve its performance.”
The researchers first conducted surface science experiments to study precisely how platinum and copper metals mix. “We were excited to find that the platinum metal dissolved in copper, just like sugar in hot coffee, all the way down to single atoms. We call such materials single atom alloys,” said Sykes.
The Tufts chemists used a specialized low temperature scanning tunneling microscope to visualize the single platinum atoms and their interaction with hydrogen. “We found that even at temperatures as low as minus 300 degrees F these platinum atoms were capable of splitting hydrogen molecules into atoms, indicating that the platinum atoms would be very good at activating hydrogen for a chemical reaction,” Sykes said.
With that knowledge, Sykes and his fellow chemists turned to long-time Tufts collaborator Maria Flytzani-Stephanopoulos, Ph.D., the Robert and Marcy Haber Endowed Professor in Energy Sustainability at the School of Engineering, to determine which hydrogenation reaction would be most significant for industrial applications. The answer, she said, was butadiene.
The model catalyst performed effectively for that reaction in vacuum conditions in the laboratory, so Flytzani-Stephanopoulos’s team took the study to the next level. They synthesized small quantities of realistic catalysts, such as platinum-copper single atom alloy nanoparticles supported on an alumina substrate, and then tested them under industrial pressure and temperatures.
“To our delight, these catalysts worked very well and their performance was steady for many days,” said Flytzani-Stephanopoulos. “While we had previously shown that palladium would do related reactions in a closed reactor system, this work with platinum is our first demonstration of operation in a flow reactor at industrially relevant conditions. We believe this approach is also applicable to other precious metals if added as minority components in copper.”
Further, the researchers found that the reaction actually became less efficient when they used more platinum, because clusters of platinum atoms have inferior selectivity compared with individual atoms. “In this case, less is more,” said Flytzani-Stephanopoulos, “which is a very good thing.”
Because platinum is at the center of many clean energy and green chemicals production technologies, such as fuel cells, catalytic converters, and value-added chemicals from bio-renewable feedstocks, the new, less expensive platinum-copper catalysts could facilitate broader adoption of such environmentally friendly devices and processes, she added.
The news release goes on to describe this cross-disciplinary partnership,
The work is the latest fruit from a long cross-disciplinary partnership between Sykes and Flytzani-Stephanopoulos.
“Maria and I met more than seven years ago and talked regularly about how to combine our fairly different fields of research into an effective collaboration across the schools of Arts and Sciences and Engineering,” said Sykes. “I had a state-of-the-art microscope that could see and manipulate atoms and molecules, and I wanted to use its unique capabilities to gain insight into industrially important chemical reactions. In the early 2000s, Maria’s group had pioneered the single-atom approach for metals anchored on oxide supports as the exclusive active sites for the water-gas shift reaction to upgrade hydrogen streams for fuel cell use. Catalyst design know-how already existed in her lab. In retrospect, it seems obvious that combining forces would be a ‘natural’ development. Together we embarked on a new direction involving single atom alloys as catalysts for selective hydrogenation reactions. Our microscope was uniquely suited for characterizing the atomic composition of surfaces. We got funding from the National Science Foundation, U.S. Department of Energy and the Tufts Collaborates initiative to pursue this new area of research.”
Sykes and Flytzani-Stephanopoulos have used this approach to design a variety of single atom alloy catalysts that have, in the last two years, sparked international interest.
“Traditionally catalyst development happens by trial and error and screening many materials,” said Flytzani-Stephanopoulos. “In this study we took a fundamental approach to understanding the atomic scale structure and properties of single atom alloy surfaces and then applied this knowledge to develop a working catalyst. Armed with this knowledge, we are now ready to compare the stability of these single atom alloy catalysts to single atom catalysts supported on various oxide or carbon surfaces. This may give us very useful criteria for industrial catalyst design.”
Silk inks containing enzymes, antibiotics, antibodies, nanoparticles and growth factors could turn inkjet printing into a new, more effective tool for therapeutics, regenerative medicine and biosensing, according to new research led by Tufts University biomedical engineers and published June 16  in the journal Advanced Materials online in advance of print.
Until now, heat used in the inkjet printing process made using silk a challenge (as it does for cellulose nanomaterials used in 3D printers, noted in my June 17, 2015 posting), from the Tufts news release,
Inkjet printing is one of the most immediate and accessible forms of printing technology currently available, according to the researchers, and ink-jet printing of biomolecules has been previously proposed by scientists. However, the heat-sensitive nature of these unstable compounds means printed materials rapidly lose functionality, limiting their use.
Enter purified silk protein, or fibroin, which offers intrinsic strength and protective properties that make it well-suited for a range of biomedical and optoelectronic applications. This natural polymer is an ideal “cocoon” that can stabilize compounds such as enzymes, antibodies and growth factors while lending itself to many different mechanically robust formats, said Fiorenzo Omenetto, Ph.D., senior author on the paper and associate dean for research and Frank C. Doble Professor of Engineering at Tufts School of Engineering.
“We thought that if we were able to develop an inkjet-printable silk solution, we would have a universal building block to generate multiple functional printed formats that could lead to a wide variety of applications in which inks remain active over time,” he said.
By using this simple approach and starting with the same base material, the research team created and tested a “custom library” of inkjet-printable, functional silk inks doped with a variety of components:
Bacterial-sensing polydiacetylenes (PDAs) printed on surgical gloves; the word “contaminated” printed on the glove changed from blue to red after exposure to E. coli
Proteins that stimulate bone growth (BMP-2) printed on a plastic dish to test topographical control of directed tissue growth
Sodium ampicillin printed on a bacterial culture to test the effectiveness of a topographical distribution of the antibiotic
Gold nanoparticles printed on paper, for possible application in photonics and biology (e.g., color engineering, surface plasmon resonance based sensing and bio-imaging)
Enzymes printed on paper to test the ability of the ink to entrain small functional biomolecules
The researchers, who included collaborators from the University of Illinois at Urbana-Champaign, foresee wide potential for future investigation and application of this technology.
For example, Omenetto envisions more work on the bio-sensing gloves, which he says could selectively react to different pathological agents. The ability to print antibiotics in topographical patterns could address the need for “smart” bandages, where therapeutics are incorporated and delivered to match a complex injury.
The published research was restricted to one ink cartridge, but the scientists believe it could extend to multi-cartridge printing combining complex functions.
Omenetto and Kaplan are pioneers in the use of silk as an alternative to plastics. Omenetto’s 2011 TED Talk called silk a “new old material” that could have a profound impact in many technical fields.