Researchers have identified the electrical switch that turns on a tadpole’s regeneration system. Someday this could possibly lead to a way to stimulate human tissue regeneration

2007-02-27: human bladders can now be grown in the lab.

2008-03-15: making materials more like biological systems: self healing.

Whichever system is adopted (and both might be, for different applications), 2 further things are needed. 1 is a way of checking that a component really has healed. The other is a way to top up the healing molecules once some of them have been used. 1 way to make healed “wounds” obvious would be to add a bit of color. A repaired area would develop a bruise. Topping up the supply of healing fluid might be done by mimicking another biological system—the network of blood capillaries that supplies living tissues with the stuff they need to thrive. Both Dr Moore and Dr Bond are attempting to borrow from nature this way. If they succeed, the machines of the future will have longer and healthier lives.

2008-09-26: The potential of regenerative medicine

engineered tissue has helped a man regrow his lost fingertip, stem cells can rebuild damaged heart muscle, and cell therapy can regenerate the skin of burned soldiers. This new, low-impact medicine comes just in time — our aging population will otherwise cause a crisis in health care systems around the world.

2008-12-21: Extracellular Matrix

Extracellular Matrix cells have been found to cause regrowth and healing of tissue.

Fingertips have been grown back with this, limbs are next.

Researchers had the idea of giving wounded muscle cells a healing boost with a substance that normally surrounds cells — the extracellular matrix. “The matrix can be thought of simply as the glue that holds all of the different cells in different tissues together. There are all these hidden signals in the matrix that instruct the cells on what to do.”

They transplanted matrix cells derived from pig bladders into the legs of patients whose muscles had been partially destroyed. Before the experimental treatment, “some of them could not get out of a chair without help. Some of them walked with a cane. This was not just a mild loss of strength. They had real problems.” After successful treatment with the matrix, 1 patient “now [rides] mountain bikes and does jumping jacks.”

Studies of deep wounds have shown that at least 2 populations of fibroblasts invade an injury during healing. Some of these cells are fibroblasts that reside in the dermis, and the others are derived from circulating fibroblast-like stem cells. Both types are attracted to the wound by signals from immune cells that have also rushed to the scene. Once in the wound, the fibroblasts migrate and proliferate, eventually producing and modifying the extracellular matrix of the area. This early process is not that dissimilar to the regeneration response in a salamander wound, but the mammalian fibroblasts produce an excessive amount of matrix that becomes abnormally cross-linked as the scar tissue matures. In contrast, salamander fibroblasts stop producing matrix once the normal architecture has been restored.

2009-03-04: they can now control how cells connect with one another in vitro and assemble themselves into 3D, multicellular microtissues.
2009-07-24: Heart Cartilage

heart cartilage growing into beating hearts, molars, ears, bladders, all in a petri dish.

2010-04-27: Wnt proteins. If you break your arm it will heal in 2 weeks.

Compared to untreated bones, a broken bone heals 3.5x faster after treatment with liposomal Wnt3a. The discovery raises the possibility of a stem cell–free route to regeneration. The researchers are now conducting mouse tests of Wnt proteins for skin wounds, stroke and heart-attack recovery, and cartilage injuries. The protein enhancement of healing is applicable to all kinds of tissues.

2010-07-26: The octogenarians on 60 minutes informing their equally ancient audience about organ regeneration. Truly mainstream now, with a hint of desperation in the reporting.
2011-11-11: future already here, not evenly distributed, etc.

A few pig cells, a single surgery and a rigorous daily workout: They’re the 3 ingredients that patients will need to re-grow fresh, functional slabs of their own muscle, courtesy of Pentagon-backed science that’s already being used to rebuild parts of people.

2012-03-03: ~10-20% of the way to growing hearts in vitro.

A heart with visible blood vessels and newly-formed tissues obtained by seeding a heart scaffold with stem cells

organ engineering here we come.

By using a process called whole organ decellularization, scientists from the University of Minnesota Center for Cardiovascular Repair grew functioning heart tissue by taking dead rat and pig hearts and reseeding them with a mixture of live cells.

2012-12-30: this is really fascinating. get a swab from 1000 people, convert it to pluripotent stem cells, install it in an array and speed up drug testing enormously.

2013-06-13: The previous state of the art was dubious, but this is properly peer-reviewed. Induced pluripotency is absolutely miraculous in its implications.

The digit bones can regenerate only if the amputated stump still has some nail stem cells, the researchers found. But the cells alone are not enough; also crucial is a zone of tissue that grows from the stem cells during normal nail growth. After amputation, this tissue sends signals that attract new nerves into the end of the stump and begin the bone regeneration process. If amputation removes the nail zone or if the signals are blocked, the digits will not regenerate.

2013-08-08: includes pictures of printed ears, kidneys, blood vessels, skin and bones.

At Wake Forest, Yoo’s and Atala’s teams built custom bioprinters that are faster than modified inkjets and can print with many more cell types—including stem cells, muscle cells, and vascular cells. They also designed one printer to create both the synthetic scaffold and tissue in one fell swoop; they’re now using it to produce intricate ears, noses, and bones.

2013-09-09: new meat source or spare parts?

2013-12-08: A lung on a chip, complete with air and “blood” flow, allows to study white blood cells in a realistic environment and design new drugs.

2013-12-21: biological printing

There are similarities to what is being achieved with biological 3D printing in other fields, but this is the first time nerve cells from the mature adult central nervous system have been successfully inkjet printed.

2014-02-19: tissue regeneration has come a long way from just 4 years ago:

the most profound change seems to be the in vivo bioreactor: bone can be grown right in the body without the need for painful grafts from other body sites.

2014-04-19: Growing new objects

Scientists and engineers around the globe dream of employing biology to create new objects. The goal might be building replacement organs, electronic circuits, living houses, or cowborgs and carborgs (my favorites) that are composed of both standard electromechanical components and novel biological components. Whatever the dream, and however outlandish, we are getting closer every day.

2014-10-29: Stomach tissue

Scientists used pluripotent stem cells to generate functional, 3D human stomach tissue in a laboratory — creating an unprecedented tool for researching the development and diseases of an organ central to several public health crises, ranging from cancer to diabetes. Scientists used human pluripotent stem cells — which can become any cell type in the body — to grow a miniature version of the stomach.

The grown tissue will allow researchers to better study illnesses of the stomach, like those that cause ulcers and even cancer. The tissue may even be used as a treatment in and of itself by way of tiny grated patches that would grow over ulcerated stomachs.

2015-01-15: Soon at your local gnc

Duke researchers have grown human skeletal muscle that contracts and responds just like native tissue to external stimuli such as electrical pulses, biochemical signals and pharmaceuticals.

2015-02-28: Brain Organoids

Researchers have used brain organoids for an investigation of microcephaly, a disorder characterized by small brain size. Using cells derived from a patient with microcephaly, the team cultured organoids that shared characteristics with the patient’s brain. Then the researchers replaced a defective protein associated with the disorder and were able to culture organoids that appeared partially cured. This is just the beginning. Researchers are using brain organoids to investigate autism, schizophrenia, and epilepsy.

2015-06-04: Limbs

The report describes engineering rat forelimbs with functioning vascular and muscle tissue. The same approach could be applied to the limbs of primates. They can maintain the matrix of all of these tissues (muscles, bone, cartilage, blood vessels, tendons, ligaments and nerves) in their natural relationships to each other, they can culture the entire construct over prolonged periods of time, and that we can repopulate the vascular system and musculature. 1.5M individuals in the US have lost a limb, and although prosthetic technology has greatly advanced, the devices still have many limitations in terms of both function and appearance.

2015-06-30: Pulsed electric fields

Researchers have devised a novel non-invasive tissue-stimulation technique using pulsed electric fields (PEF) to generate new skin tissue growth. The technique produces scarless skin rejuvenation and may revolutionize the treatment of degenerative skin diseases

2015-08-01: Organoids

Madeline Lancaster realized that she had accidentally grown a brain. Since the late 2000s, biologists have grown a wide variety of rudimentary organs to understand development and for medical uses.

2015-09-12: 3D printed rib cage

A Spanish cancer patient has received a 3D-printed titanium sternum and rib cage. Suffering from a chest wall sarcoma (a type of cancerous tumor that grows, in this instance, around the rib cage), the 54 year old man needed his sternum and a portion of his rib cage replaced. This part of the chest is notoriously tricky to recreate with prosthetics, due to the complex geometry and design required for each patient.

2015-09-23: Organoids

A new technique for building organoids (tiny models of human tissues) turns human cells into LEGO bricks: These mini-tissues can be used to study how particular structural features of tissue affect normal growth or go awry in cancer. They could be used for therapeutic drug screening and to help teach researchers how to grow whole human organs.

2015-11-05: embryoid body printing

Scientists have developed a 3D printing method capable of producing embryoid bodies — highly uniform “blocks” of embryonic stem cells. These cells, which are capable of generating all cell types in the body, could be used to build tissue structures and potentially even micro-organs.

2015-11-06: Simulated blood vessels

Scientists have designed an innovative structure containing an intricate microchannel network of simulated blood vessels that solves one of the biggest challenges in regenerative medicine: How to deliver oxygen and nutrients to all cells in an artificial organ or tissue implant that takes days or weeks to grow in the lab prior to surgery.

2016-03-11: Eye lens

Scientists grow eye lens from patients’ own stem cells, restoring vision. In pioneering new cataract treatment of 12 pediatric patients, the eye grew a new lens from its own stem cells after cloudy lens was removed.

2016-04-09: Mammal Limb regeneration

We have an encouraging proof of concept that these elements possess all the sequences necessary to work with mammalian machinery after an injury. Genetic elements like these could be combined with genome-editing technologies to improve the ability of humans to repair and regrow damaged or missing body parts.

2017-02-27: Printed skin

This new human skin is one of the first living human organs created using bioprinting to be introduced to the marketplace. It replicates the natural structure of the skin, with a first external layer, the epidermis with its stratum corneum, which acts as protection against the external environment, together with another thicker, deeper layer, the dermis. This last layer consists of fibroblasts that produce collagen, the protein that gives elasticity and mechanical strength to the skin.

2017-07-28: could have been stolen from the westworld opening

2017-11-13: Brains on Mice Substrate

“These micro quasi-brains are revolutionizing research on human brain development and diseases from Alzheimer’s to Zika, but the headlong rush to grow the most realistic, most highly developed brain organoids has thrown researchers into uncharted ethical waters….In the previously unreported experiments implanting human brain organoids into lab rodents, most of the transplants survived….More notably, the human organoids implanted into mice connected to the rodent’s circulatory system, making this the first reported vascularization. And mature neurons from the human brain organoid sent axons, the wires that carry electrical signals from 1 neuron to another, into “multiple regions of the host mouse brain”.

2018-01-03: Bone gap filler

US Army researchers are using a synthetic bone gap filler that heals bones and reduces infection by infusing those grafts with a variety of antimicrobials, hoping to figuratively bridge the gap between current regenerative techniques and the ideal: people regrowing lost limbs.

2018-04-28: Pig brain revival 1

Yale University neuroscientist Nenad Sestan disclosed that a team he leads had experimented on between 100 and 200 pig brains obtained from a slaughterhouse, restoring their circulation using a system of pumps, heaters, and bags of artificial blood warmed to body temperature. BrainEx technology involves connecting a brain to a closed loop of tubes that circulate heated artificial blood throughout the brain’s vessels – allowing oxygen to flow to cells even deep in the brain. This is similar to the way scientists preserve other organs such as heart or lungs for transplants.

2018-06-15: Human limb regrowth

We have enriched for a pluripotent stem cell population, which opens the door to a number of experiments that were not possible before. The fact that the marker we discovered is expressed not only in planarians but also in humans suggests that there are some conserved mechanisms that we can exploit.

2018-12-03: Pig-Human Hybrid Brains

If a pig embryo is given an infusion of human stem cells, which can become nearly any tissue in the animal’s body, are we potentially creating animals with partial human brains? Could we accidentally bestow human-style awareness into a pig? Could human cells find their way into the sperm and egg cells of animals? And if so, what are the consequences?

2019-07-03: Pig brain revival 2

The thorniest issue centered on consciousness and whether the Yale team, inadvertently, might somehow have figured out a way to elicit it from dead flesh. Brain death — and thus complete loss of consciousness — has become something of a moving target. Patients we once thought were in deep comas as a result of a traumatic brain injury are actually able to communicate

2019-08-01: Pig brain revival 3

“Scientists Are Giving Dead Brains New Life. What Could Go Wrong?” (““What’s happened, I’d argue, is that a lot of things about the brain that we once thought were irreversible have turned out not necessarily to be so.””

2020-09-04: it is possible to induce the growth of neurons.
2021-05-15: Bioelectricity for regrowth

“Regeneration is not just for so-called lower animals”. Deer can regenerate antlers; humans can regrow their liver. “You may or may not know that human children below the age of 11 are able to regenerate their fingertips”. Why couldn’t human-growth programs be activated for other body parts—severed limbs, failed organs, even brain tissue damaged by stroke?

Levin’s work involves a conceptual shift. The computers in our heads are often contrasted with the rest of the body; most of us don’t think of muscles and bones as making calculations. But how do our wounds “know” how to heal? How do the tissues of our unborn bodies differentiate and take shape without direction from a brain? When a caterpillar becomes a moth, most of its brain liquefies and is rebuilt—and yet researchers have discovered that memories can be preserved across the metamorphosis. “What is that telling us?”. Among other things, it suggests that limbs and tissues besides the brain might be able, at some primitive level, to remember, think, and act. Other researchers have discussed brainless intelligence in plants and bacterial communities, or studied bioelectricity as a mechanism in development. But Levin has spearheaded the notion that the 2 ideas can be unified: he argues that the cells in our bodies use bioelectricity to communicate and to make decisions among themselves about what they will become.

2022-03-18: State of tissue engineering

But all this illustrates the trickiness of making new human tissues from stem cells. Recapitulating human tissue development is no easy task; the amount of signaling that goes into these processes is mind-boggling. And as these beta-cell efforts show, we don’t quite understand the details, both what to leave in and what to leave out. In this case, we ended up with something that still seems to work fairly well, somehow, but many times you won’t. So all the talk about growing and transplanting new stem-cell derived nerve tissue, new liver and pancreas tissue, new cardiac muscle, etc. still (after all these years) comes under the “Should be possible but not really yet” heading. It is a long hard road, and we’re only partway along it – we can make islet-ish tissue, neural-like tissue, muscle-oid cells, that sort of thing, but are these useful for human therapy or not? We might be within range of useful effects with these new islets, but as mentioned, that remains to be proven. Overall, it’s a good thing that the hype has died down over the years so the real work can go on.

2022-06-02: printed ear

A 20-year-old woman who was born with a small and misshapen right ear has received a 3D printed ear implant made from her own cells. The clinical trial, which includes 11 patients, is still ongoing, and it’s possible that the transplants could fail or bring unanticipated health complications. But since the cells originated from the patient’s own tissue, the new ear is not likely to be rejected by the body.

2022-07-21: Nerves not required for limb regeneration

When the limbs were suspended, even though they still had lots of nerves and could move around, they couldn’t actually put pressure on their limbs so the digit tips wouldn’t regenerate. It just completely inhibited regeneration. But once the load returns, there will be a couple weeks of delay, but then they’ll begin to regenerate. Mice can still regrow their digit tips even without any nerves in their affected digit — the process was just a bit slower. This suggests that nerves aren’t actually essential to mammal regeneration.

“These 2 studies counteract the 200 year dogma that you need nerves to regenerate. What replaces it in mammals is that you need mechanical loading, not nerves.”

2022-08-05: OrganEx

Researchers have restored circulation and cellular activity in the vital organs of pigs, such as the heart and brain, 1 hour after the animals died. The research challenges the idea that cardiac death — which occurs when blood circulation and oxygenation stops — is irreversible, and raises ethical questions about the definition of death. The work follows 2019 experiments by the same scientists in which they revived the disembodied brains of pigs 4 hours after the animals died, calling into question the idea that brain death is final.
1 hour after the pigs died, they restarted the ventilators and anesthesia. Some of the pigs were then attached to the OrganEx system; others received no treatment or were hooked up to an extracorporeal membrane oxygenation (ECMO) machine, which some hospitals use in a last-ditch effort to supply oxygen to and remove CO2 from the body.
After 6 hours, circulation had restarted much more effectively in pigs that received the OrganEx solution than in those that received ECMO or no treatment. Oxygen had begun flowing to tissues all over the bodies of the OrganEx animals, and a heart scan detected some electrical activity and contraction. But the heart had not fully restarted, and it’s unclear what exactly it was doing in those animals.

2022-08-12: Synthetic mouse embryos

scientists have created mouse embryos in the lab without using any eggs or sperm and watched them grow outside the womb. To achieve this feat, the researchers used only stem cells. The breakthrough experiment, took place in a specially designed bioreactor that serves as an artificial womb for developing embryos. Within the device, embryos float in small beakers of nutrient-filled solution, and the beakers are all locked into a spinning cylinder that keeps them in constant motion. This movement simulates how blood and nutrients flow to the placenta. The device also replicates the atmospheric pressure of a mouse uterus.

2022-10-13: Human brain organoids in rat substrate are much more human-like than in vitro

Neuroscientists have found a new way to study human neurons — by transplanting human brainlike tissue into rats that are just days old, when their brains have not yet fully formed. The researchers show that human neurons and other brain cells can grow and integrate themselves into the rat’s brain, becoming part of the functional neural circuitry that processes sensations and controls aspects of behaviors.

Using this technique, scientists should be able to create new living models for a wide range of neurodevelopmental disorders, including at least some forms of autism spectrum disorder. The models would be just as practical for neuroscientific lab studies as current animal models are but would be better stand-ins for human disorders because they would consist of real human cells in functional neural circuits. They could be ideal targets for modern neuroscience tools that are too invasive to use in real human brains.

2023-03-11: Organoid Intelligence

• Biological computing (or biocomputing) could be faster, more efficient, and more powerful than silicon-based computing and AI, and only require a fraction of the energy.
• ‘Organoid intelligence’ (OI) describes an emerging multidisciplinary field working to develop biological computing using 3D cultures of human brain cells (brain organoids) and brain-machine interface technologies.
• OI requires scaling up current brain organoids into complex, durable 3D structures enriched with cells and genes associated with learning, and connecting these to next-generation input and output devices and AI/machine learning systems.
• OI requires new models, algorithms, and interface technologies to communicate with brain organoids, understand how they learn and compute, and process and store the massive amounts of data they will generate.
• OI research could also improve our understanding of brain development, learning, and memory, potentially helping to find treatments for neurological disorders such as dementia.
• Ensuring OI develops in an ethically and socially responsive manner requires an ‘embedded ethics’ approach where interdisciplinary and representative teams of ethicists, researchers, and members of the public identify, discuss, and analyze ethical issues and feed these back to inform future research and work.

2023-07-07: Organ vitrification and reanimation worked (barely)

When vitrifying, scientists first infuse the organ or tissue with magnetic nanoparticles and safeguarding chemicals called cryoprotective agents that serve as a kind of antifreeze. Afterward, they cool it quickly — 24 degrees Celsius per minute — to bypass the formation of cell-shredding ice crystals and directly enter a glass-like state. Bischof and his colleagues have spent years developing technology that can rewarm vitrified materials fast enough to avoid ice-crystal formation in the physical transition back from glass. This rewarming, critically, also must be uniform, to avoid an organ cracking and splitting from its outside surfaces being too different a temperature from its core — like an ice cube in a glass of room-temperature water.
That’s not to say the nanowarmed kidneys performed exactly like any other. They worked — but they didn’t work perfectly. The experimental kidneys produced urine within 45 minutes of transplantation, compared to a few minutes for their fresh counterparts. And for the first days after surgery, they were slower to clear out creatinine, a chemical waste product that kidneys remove from the body. Though “by 3 weeks, they look like normal kidneys”.

“The biggest issue is that the kidneys were, in fact, badly damaged. The function of those kidneys was cut by 50%. These were kidneys in the peak of life, in perfect health — and they barely made it. If they’d been any more damaged than they were they wouldn’t have made it.”

On the other hand, the degree to which the kidneys did heal and recover was “remarkable and encouraging.” In the paper, the researchers also noted that because they ended the study 30 days post-transplant, they weren’t able to assess longer-term survival.

The researchers plan to scale their cryopreservation method up to pig organs — a size change, kidney-wise, from a large grape (in rats) to about a pear (in pigs). As they go, they will continue to study whether rewarmed animal organs recover their original physiological, chemical, and electrical properties.

Down the line, if all goes well, the future might hold living banks where organs, skin, nerves, blood vessels, cartilage and stem cells are preserved in liquid nitrogen for years until they’re matched with the right patients.

2023-07-28: Xenotransplantation progress

Genetically modified xenografts are one of the most promising solutions to the discrepancy between the numbers of available human organs for transplantation and potential recipients. To date, a porcine heart has been implanted into only 1 human recipient. Here, using 10-gene-edited pigs, we transplanted porcine hearts into 2 brain-dead human recipients and monitored xenograft function, hemodynamics and systemic responses over the course of 66 hours. Although both xenografts demonstrated excellent cardiac function immediately after transplantation and continued to function for the duration of the study, cardiac function declined postoperatively in one case, attributed to a size mismatch between the donor pig and the recipient. For both hearts, we confirmed transgene expression and found no evidence of cellular or antibody-mediated rejection, as assessed using histology, flow cytometry and a cytotoxic crossmatch assay. Moreover, we found no evidence of zoonotic transmission from the donor pigs to the human recipients. While substantial additional work will be needed to advance this technology to human trials, these results indicate that pig-to-human heart xenotransplantation can be performed successfully without hyperacute rejection or zoonosis.

2023-09-29: Cognition without a brain

A tiny jellyfish has, for the first time, demonstrated a mighty cognitive capacity — the ability to learn by association. Although it has no central brain, the finger-tip-sized Caribbean box jellyfish (Tripedalia cystophora) can be trained to associate the sensation of bumping into something with a visual cue, and to use the information to avoid future collisions.