An August 14, 2025 news item on ScienceDaily announced research into burn care from Sweden’s Linköping University,
Researchers have created what could be called “skin in a syringe.” The gel containing live cells can be 3D printed into a skin transplant, as shown in a study conducted on mice. This technology may lead to new ways to treat burns and severe wounds. The study was led from the Center for Disaster Medicine and Traumatology and Linköping University in Sweden, and has been published in Advanced Healthcare Materials.
As long as we have a healthy skin, we do not give it much thought. However, if we get major wounds or other injuries, it becomes clear that the skin is the body’s protection from the outside world. Helping the body restore the skin barrier after a serious burn can therefore be a matter of life and death.
Large burns are often treated by transplanting a thin layer of the top part of the skin, the epidermis. This is basically composed of a single cell type. Transplanting only this part of the skin leads to severe scarring.
Under the epidermis there is a thicker and more advanced layer of skin called the dermis. It has blood vessels, nerves, hair follicles and other structures necessary for skin function and elasticity. However, transplanting also the dermis is rarely an option, as the procedure leaves a wound as large as the wound to be healed.
The trick is to create new skin that does not become scar tissue but a functioning dermis.
“The dermis is so complicated that we can’t grow it in a lab. We don’t even know what all its components are. That’s why we, and many others, think that we could possibly transplant the building blocks and then let the body make the dermis itself,” says Johan Junker, researcher at the Swedish Center for Disaster Medicine and Traumatology and docent in plastic surgery at Linköping University, who led the study published in Advanced Healthcare Materials.
The most common cell type in the dermis, the connective tissue cell or fibroblast, is easy to remove from the body and grow in a lab. The connective tissue cell also has the advantage of being able to develop into more specialised cell types depending on what is needed. The researchers behind the study provide a scaffold by having the cells grow on tiny, porous beads of gelatine, a substance similar to skin collagen. But a liquid containing these beads poured on a wound will not stay there.
The researchers’ solution to the problem is mixing the gelatine beads with a gel consisting of another body-specific substance, hyaluronic acid. When the beads and gel are mixed, they are connected using what is known as click chemistry. The result is a gel that, somewhat simplified, can be called skin in a syringe.
“The gel has a special feature that means that it becomes liquid when exposed to light pressure. You can use a syringe to apply it to a wound, for example, and once applied it becomes gel-like again. This also makes it possible to 3D print the gel with the cells in it,” says Daniel Aili, professor of molecular physics at Linköping University, who led the study together with Johan Junker.
In the current study, the researchers 3D-printed small pucks that were placed under the skin of mice. The results point to the potential of this technology to be used to grow the patient’s own cells from a minimal skin biopsy, which are then 3D-printed into a graft and applied to the wound.
“We see that the cells survive and it’s clear that they produce different substances that are needed to create new dermis. In addition, blood vessels are formed in the grafts, which is important for the tissue to survive in the body. We find this material very promising,” says Johan Junker.
Blood vessels are key to a variety of applications for engineered tissue-like materials. Scientists can grow cells in three-dimensional materials that can be used to build organoids, i.e. mini versions of organs. But there is a bottleneck as concerns these tissue models; they lack blood vessels to transport oxygen and nutrients to the cells. This means that there is a limit to how large the structures can get before the cells at the centre die from oxygen and nutrient deficiency.
The LiU researchers may be one step closer to solving the problem of blood vessel supply. In another article, also published in Advanced Healthcare Materials, the researchers describe a method for making threads from materials consisting of 98 per cent water, known as hydrogels.
“The hydrogel threads become quite elastic, so we can tie knots on them. We also show that they can be formed into mini-tubes, which we can pump fluid through or have blood vessel cells grow in,” says Daniel Aili.
The mini-tubes, or the perfusable channels as the researchers also call them, open up new possibilities for the development of blood vessels for e.g. organoids.
Lars Kölby, professor of plastic surgery at Sahlgrenska University Hospital in Gothenburg, also participated in the project. The research has received funding from, among others, the Erling-Persson Foundation, the European Research Council (ERC), the Swedish Research Council and the Knut and Alice Wallenberg Foundation.
Caption: The researchers 3D-printed small pucks of the gel with cells in it. Credit: Magnus Johansson/Linköping University
Here are links to and citations for both papers in the order in which they are mentioned in the press release,
Biphasic Granular Bioinks for Biofabrication of High Cell Density Constructs for Dermal Regeneration by Rozalin Shamasha, Sneha Kollenchery Ramanathan, Kristin Oskarsdotter, Fatemeh Rasti Boroojeni, Aleksandra Zielińska, Sajjad Naeimipour, Philip Lifwergren, Nina Reustle, Lauren Roberts, Annika Starkenberg, Gunnar Kratz, Peter Apelgren, Karin Säljö, Jonathan Rakar, Lars Kölby, Daniel Aili, Johan Junker. Advanced Healthcare Materials Volume 14, Issue 21 August 19, 2025 2501430 DOI: https://doi.org/10.1002/adhm.202501430 First published online: 12 June 2025
This paper is open access.
Printing and Rerouting of Elastic and Protease Responsive Shape Memory Hydrogel Filaments by Philip Lifwergren, Viktoria Schoen, Sajjad Naeimipour, Lalit Khare, Anna Wunder, Hanna Blom, Jose G. Martinez, Pierfrancesco Pagella, Anders Fridberger, Johan Junker, Daniel Aili. Advanced Healthcare Materials Volume 14, Issue 22 August 28, 2025 2502262 DOI: https://doi.org/10.1002/adhm.202502262 First published online: 20 June 2025
The paper’s graphical abstract presents some intriguing visuals,
Caption: Schematic representation of the A/B-sides multi-biological functional hydrogel patch. Credit: Wenle Chen from Shenzhen Second People’s Hospital, First Affiliated Hospital of Shenzhen University and Yu Wang from Wenzhou Institute, University of Chinese Academy of Sciences.
A research team from Shenzhen University, University of Chinese Academy of Sciences and Hong Kong Polytechnic University has developed an innovative, bioinspired hydrogel patch with controllable adhesion properties to enhance soft tissue repair and prevent adhesions. Inspired by octopus suction cups and the eyeball surfaces, this patch features a dual-sided design: one side offers adjustable, revocable adhesion, while the other provides anti-adhesive functions. In vivo [animal] experiments demonstrate its effectiveness in reducing inflammation, promoting tissue healing, and allowing repositioning during surgical procedures, marking a significant advancement in biomedical materials.
Tissue repair required in scenarios such as trauma, post-operative of tumors is a common challenge for human healthcare. Soft tissue injuries and surgical wounds often face challenges such as excessive tissue adhesion, which can complicate healing and cause secondary complications. Traditional patches and sutures either lack adequate adhesion or induce unwanted tissue sticking, leading to inflammation and hindered recovery. There is an urgent need for biomaterials that can intelligently balance strong tissue integration with the ability to detach or reposition easily, matching the dynamic environment of internal tissues.
In this context, hydrogel patches, owing to their exceptional biocompatibility and potential adhesive properties, are expected to become ideal materials for soft tissue repair. These materials can gradually degrade, naturally integrate with human tissues, and easily incorporate drugs or growth factors to promote angiogenesis, thereby enhancing the speed and quality of tissue healing. In general, the common hydrogel patches can be divided into adhesive ones and anti-adhesive ones. Adhesive patches can form rapid and strong covalent bonds with moist tissue to promote tissue regeneration, whose further applications are limited by excessive tissue adhesion. While anti-adhesive patches can address the tissue adhesion problem by hydrophobic surface modification or coarse structure design, they are difficult to fit the wounds tightly for treatment. Hence, it is necessitating to design an anisotropic patch combining the merits of promoting tissue regeneration and anti-adhesive function.
The Solution: Drawing inspiration from nature, interdisciplinary research team engineered a novel hydrogel patch that mimics natural mechanisms using suction cup-like structures for physical, reversible adhesion and covalent bonds for permanent fixation. The patch’s adhesive side uses microstructures that generate negative pressure for temporary adhesion, allowing surgeons to adjust its position during surgery, once aligned, chemical reactions secure a firm, covalent attachment. The other side is made of highly hydrated, anti-adhesive materials to prevent surrounding tissue from sticking undesirably. Additionally, the patch absorbs positively charged inflammatory factors and provides sustained drug release, further aiding in inflammation reduction and tissue regeneration.
The bioinspired system features a multi-functional, dual-sided hydrogel patch composed of polyacrylic acid-NHS for the adhesive surface, and polyvinyl alcohol (PVA) combined with polyethylene glycol diacrylate (PEGDA) for the anti-adhesive barrier. Its porous network not only enables physical and chemical adhesion but also captures inflammatory cytokines, fostering a more favourable healing environment. In vivo tests in animal models confirmed the patch’s strong, controllable adhesion, its ability to prevent unwanted tissue adhesion, and its capacity to promote faster, healthier tissue repair.
The Future: This innovative hydrogel patch represents a significant step forward in the field of soft tissue repair. It combines the benefits of promoting tissue regeneration and preventing adhesion into one device. Future research will focus on optimizing the patch’s properties for specific clinical applications, such as abdominal wall defect repair and other dynamic wound management scenarios. The development of advanced manufacturing technologies like 3D bioprinting could also enable the customization of patch geometry for specific anatomical structures. Additionally, the exploration of environmentally adaptive intelligent components could lead to a more precise control of adhesion and drug release that aligns with the tissue regeneration process.
The Impact: This hydrogel patch offers a new paradigm for soft tissue repair with its “revocable” adhesion properties. It has the potential to significantly reduce clinical adhesion scores, effectively reduce inflammation, promote wound healing, and enhance collagen deposition. The successful integration of controllable adhesion and anti-adhesion functions in one patch could revolutionize the way we approach soft tissue repair and adhesion prevention in clinical settings.
UBC Okanagan researchers have developed a 3D bio-printed model that closely mimics the complexity of natural lung tissue, an innovation that could transform how scientists study lung disease and develop new treatments.
Dr. Emmanuel Osei, Assistant Professor in the Irving K. Barber Faculty of Science, says the model produces tissue that closely resembles the complexity of a human lung, enabling improved testing of respiratory diseases and drug development.
“To conduct our research and the testing that’s required—where we’re studying the mechanisms of complex lung diseases to eventually find new drug targets—we need to be able to make models that are comparable to human tissues.”
The research team used a bioink composed of light-sensitive polymer-modified gelatin and a polymer called polyethylene glycol diacrylate to 3D print a hydrogel that includes multiple cell types and channels to recreate vessels, mimicking the structure of a human airway.
Once printed, the hydrogel performs much like the complex mechanical properties of lung tissue, improving how researchers study cellular responses to stimuli.
“Our goal was to create a more physiologically relevant in vitro model of the human airway,” says Dr. Osei, who also works with UBC’s Centre for Heart Lung Innovation. “By integrating vascular components, we can better simulate the lung environment, which is crucial for studying diseases and testing therapeutics.”
Dr. Osei explains that when someone has lung cancer, a surgeon—with the patient’s consent—can remove the cancerous section along with some normal lung tissue and provide these samples to researchers.
“However, a researcher has no control over how much tissue they will receive,” he explains. “They might get a small piece of tissue which they bring to the lab and add various chemicals for testing. Now, with 3D bioprinting, we can isolate cells from these donated tissues and potentially recreate additional tissue and test samples to conduct research in our labs and not rely on or wait for contributed tissues.”
Dr. Osei says many forms of lung disease currently have no cure, including chronic obstructive pulmonary disease, asthma, idiopathic pulmonary fibrosis and cancer. Being able to establish models that allow for testing is a significant advancement in respiratory disease research and drug development.
Published in Biotechnology and Bioengineering, in collaboration with Mitacs [nonprofit Canadian national research organization] and supported by the Providence Health Care [Catholic health care provider in Vancouver, British Columbia], the study is a step toward assessing aspects of lung diseases such as scarring and inflammation, and may lead to future cures for various illnesses.
The paper detailed tests, including exposing the bio-printed 3D model to cigarette smoke extract, allowing the researchers to observe increases in pro-inflammatory cytokines, or markers of inflammatory responses to nicotine in lung tissue.
“The fact that we’ve been able to create the model, then use particular triggers like cigarette smoke, to demonstrate how the model will react and mimic aspects of lung disease is a significant advancement in studying complex mechanisms of lung disease that will aid in studying how we treat them,” says Dr. Osei.
“Our model is complex, but due to the reproducibility and optimal nature of bio-printing, it can be adapted to include additional cell types or patient-derived cells, making it a powerful tool for personalized medicine and disease modelling.”
Dr. Osei notes that moving forward with this work puts his research team in a unique position to collaborate with colleagues such as UBC’s Immunobiology Eminence Research Excellence Cluster, biotechnology companies and those with an interest in advancing bioartificial models.
I have two stories about electronic skin (e-skin or artificial skin), each featuring a very different approach to developing the technology.
Leather for electronic skin
Michael Berger’s May 28, 2025 Nanowerk Spotlight article provides context for the research into producing artificial (electronic) skin using leather as the base,
Flexible electronics are reshaping how humans interact with machines, creating new possibilities for systems that conform to the body and respond intelligently to physical stimuli. Among the most ambitious goals in this field is the development of electronic skin—e-skin—that replicates the sensory and protective functions of biological tissue.
Real skin does more than just sense touch; it buffers mechanical impacts, regulates temperature, and shields the body from harmful radiation. Replicating all these functions in a single synthetic material has proven technically complex. Most artificial skins focus narrowly on pressure sensing or surface temperature monitoring, often falling short when required to provide mechanical robustness or electromagnetic shielding.
A variety of material systems have been explored in pursuit of a true e-skin, including hydrogels, silicone elastomers, carbon nanotube composites, and layered polymer matrices. While many of these have achieved impressive sensitivity to pressure or temperature, their mechanical fragility, structural instability, or limited responsiveness under stress have restricted their practical use. Some efforts have turned to bio-derived substrates like cellulose or silk. Although lightweight and flexible, these materials are often fragile and lack the structural hierarchy needed for reliable multifunctionality.
Leather—processed animal skin—presents an intriguing alternative. It possesses intrinsic toughness, flexibility, and a multilayered collagen fiber structure that resembles the dermal framework of natural skin. Its use in clothing and protective gear underscores its reliability.
However, until now, efforts to adapt leather for flexible electronics have been hampered by poor structural integration, limited sensitivity under dynamic conditions, and weak electromagnetic shielding. These limitations have prevented leather from advancing beyond a passive substrate into a truly intelligent material capable of emulating skin’s full range of functions.
…
Berger’s May 28, 2025 article goes on to describe a new approach to transforming leather into e-skin,
In a study published in Advanced Functional Materials (“Exceed the Traditional Dead Leather to Intelligent E‐Skin”), researchers from the University of Science and Technology of China and Hong Kong Baptist University present a leather-based composite that addresses these limitations. By integrating silver nanostructures and a viscoelastic polymer into natural leather, the team developed a multifunctional e-skin that unites pressure sensing, thermal control, impact protection, and electromagnetic shielding in a single material platform.
This composite, referred to as LAP (Leather/Ag/Polyborosiloxane Elastomer), mirrors the layered anatomy of human skin. The leather forms the outer protective surface, analogous to the epidermis. Embedded within this layer is a hybrid network of silver nanowires and silver flakes. These fill the gaps between collagen fibers, creating a dense, conductive network that functions like the skin’s dermis. The inner layer comprises a polyborosiloxane elastomer—a viscoelastic material that stiffens upon impact, much like the hypodermis’ role in absorbing mechanical shocks.
The conductive layer benefits from the combination of one-dimensional nanowires and two-dimensional flakes. The flakes act as broad conductive platforms while the nanowires link them, forming a three-dimensional network. This arrangement significantly enhances conductivity and mechanical cohesion. The optimal ratio of silver nanowires to flakes—determined to be 1:2—yielded both low resistance and high tensile strength. The material reached a tensile strength of 9.28 MPa at a silver content of 5.0 mg/cm², nearly doubling the strength of the underlying leather-polymer base. Fracture strains of up to 70.8% demonstrate the composite’s flexibility and capacity for wearable use.
…
One of the most distinctive capabilities of the LAP e-skin is its dual-mode sensing response. Under slow compression, the conductive network densifies, reducing resistance and enabling precise piezoresistive sensing. The sensor detected strains as low as 2% with consistent signal output over 500 cycles. Under high-speed impact, however, the network momentarily fractures, increasing resistance instead. This difference allows the material to distinguish between light contact and sudden impacts, a feature that mimics how real skin perceives touch versus pain.
…
This study illustrates how biologically inspired materials can be reengineered to achieve functional integration across sensing, protection, and regulation domains. The choice to reconfigure leather—already optimized by evolution for wearability and toughness—provides a structurally rich and mechanically resilient platform. By layering conductive and responsive components onto this substrate, the researchers have constructed a versatile material that pushes the capabilities of e-skin systems toward those of natural tissue.
Exceed the Traditional Dead Leather to Intelligent E-Skin by Yue Yao, Ziyang Fan, Xinglong Gong, Danyi Li, Wei Yang, Ken Cham-Fai Leung, Xinyi Wang, Shuai Liu, Junjie Yang, Shouhu Xuan. Advanced Functional Materials DOI: https://doi.org/10.1002/adfm.202500572 First published online: 24 May 2025
Researchers at DTU have made a significant achievement by developing a new kind of electronic material that behaves almost exactly like human skin. That kind of substance could be useful in soft robotics, medicine, and healthcare.
Picture electronic devices that heal the way our skin repairs itself. Researchers at DTU have developed a new material that makes it possible—a flexible, tough and self-healing material that may in future come into use in the healthcare sector, in robotics and much more. This new material overcomes the weaknesses of the rigid, brittle electronic materials currently used, which can’t repair themselves.
By dint of an innovative approach, the scientists at DTU have combined the exceptional properties of graphene, a two-dimensional carbon form that is extremely strong, and has great electrical conductivity, with the see-through polymer PEDOT: PSS, that is also electrically conductive and is, for example, used in flexible electronics and sometimes as transparent electrodes in solar cells. When these two parts are mixed, they turn what’s usually a weak, jellylike material into a solid, flexible, self-healing electronic material.
“The devices that exist today and have self-healing, soft, and responsive properties often fail to seamlessly integrate all these attributes into a single, scalable, and cohesive platform. And that is what I believe we have accomplished,” says Alireza Dolatshahi-Pirouz, Associate Professor at DTU Health Tech and lead author of a recent paper in Advanced Science, detailing their accomplishment: Self‐Maintainable Electronic Materials with Skin‐Like Characteristics Enabled by Graphene‐PEDOT:PSS Fillers.
“Our skin-inspired material is multifunctional, endowed with the desired tactile properties, specifically designed for the usage of electronic devices. This may open the doors to the more advanced and versatile technologies that could more closely mingle with the human body and the surroundings.”
Flexible and self-repairing
Among the most promising attributes of the new material is its ability to self-heal. If it is damaged, it can heal in a matter of seconds, the way the human skin heals after, say, a cut. On top of that, the material is extremely malleable and can be stretched up to six times beyond its original length and still bounce back. This makes it well suited for integration within wearable and soft robotic devices, which require that materials can be moved and bent without diminishing their performance.
It can also control heat and detect a range of environmental factors, such as pressure, temperature and pH levels, which could make it beneficial for health monitoring systems that must keep track of vital signs and adjust to body changes.
Electronics built from this material could therefore be amorphous and shape-changing, capable of adapting to their environment, the researchers say, and able to recover from damage the way biological systems do.
“The fact that the material can self-heal, regulate heat, and monitor vital signs makes it suitable to be used in a large range of equipments, says Alireza Dolatshahi-Pirouz:
“Space suits spring to mind, but I believe that we will find the most relevant uses for the individual citizen within healthcare. We could, for instance, incorporate it in bandages that would monitor how a wound is healing, or in devices that continuously track heart rate and temperature. The stretchable nature of the material makes it ideal for minimally invasive surgery or implantable applications. And we could easily imagine prosthetics that are more comfortable to wear and have better performance.”
At present, the researchers are continuing their work and investigating methods to make it on a larger scale, aimed at setting the stage for real-life applications.
By combining graphene and a polymer blend, DTU researchers have developed a self-healing electronic material that mimics the properties of skin. Illustration: Daniel Müller.
The Israeli team working on this regenerative medicine project has already (in 2022) been successful with mice. Diana Bletter’s August 21, 2025 Times of Israel article, excerpts of which can be found later in this posting, added some details that I appreciated. That said, the press release is quite accessible and informative.
What if we could restore the ability to walk to people paralyzed by injury or illness? This vision is now moving closer to reality. Three years ago, Tel Aviv University researchers succeeded in engineering a human spinal cord in the lab for the first time. Since then, progress has been rapid, with animal trials showing unprecedented success. Now, for the first time, the technology is set to be tested in human patients.
Prof. Tal Dvir, of TAU’s Sagol Center for Regenerative Biotechnology, head of the Nanotechnology Center, and Chief Scientist of the biotech company Matricelf, explains: “The spinal cord is made up of nerve cells that transmit electrical signals from the brain to every part of the body. When the spinal cord is torn due to trauma — from a car accident, a fall, or a battlefield injury — this chain is broken. Think of it like an electrical cable that’s been cut: if the two parts don’t touch, the electrical signal can’t pass. The cable won’t carry electricity, and in the same way, the person can’t transmit the signal beyond the site of the injury.”
This is one of the few injuries in the human body with no natural ability to regenerate. “Neurons are cells that do not divide and do not renew themselves. They are not like skin cells, which can repair themselves after injury. They are more similar to heart cells: once damage occurs, the body cannot restore them,” notes Prof. Dvir.
Engineering a Personalized Implant
To overcome this challenge, the TAU researchers developed a fully personalized process. Blood cells are taken from the patient and reprogrammed through genetic engineering to behave like embryonic stem cells, capable of becoming any type of cell in the body.
Meanwhile, fat tissue from the same patient is used to extract substances such as collagen and sugars. These are used to produce a unique hydrogel. “The beauty of this gel is that it’s also personalized, just like the cells. We take the cells that we’ve reprogrammed into embryonic-like stem cells, place them inside the gel, and mimic the embryonic development of the spinal cord,” says Prof. Dvir.
The result is a complete three-dimensional implant. “At the end of the process, we don’t just turn the cells into motor neurons — because cells alone won’t help us — but into three-dimensional tissue: neuronal networks of the spinal cord. After about a month, we obtain a 3D implant with many neurons that transmit electrical signals. These 3D tissues are then implanted into the damaged area.”
Visualization of the next stage of the research – human spinal cord implants for treating paralysis (Photo: Sagol Center for Regenerative Biotechnology)
From Animals to Human Patients
The researchers first tested the implant in lab animals. “We showed that we can treat animals with chronic injuries. Not animals that were injured just recently, but those we allowed enough time to pass — like a person more than a year after an injury. More than 80% of the animals regained full walking ability,” Prof. Dvir explains.
Encouraged by these results, the team submitted the findings to Israel’s Ministry of Health. “About six months ago we received preliminary approval to begin compassionate-use trials with eight patients. We decided, of course, that the first patient would be Israeli. This is undoubtedly a matter of national pride. The technology was developed here in Israel, at Tel Aviv University and at Matricelf, and from the very beginning it was clear to us that the first-ever surgery would be performed in Israel, with an Israeli patient.” he says.
Looking Ahead
The first implant in a human patient is expected within about a year. For the initial trials, the team will focus on patients whose paralysis is relatively recent — within about a year of injury. “Once we prove that the treatment works — everything is open, and we’ll be able to treat any injury,” says Prof. Dvir.
Behind the initiative are key figures from both academia and industry. Prof. Dvir founded Matricelf in 2019 together with Dr. Alon Sinai, based on the revolutionary organ engineering technology developed at TAU under a licensing agreement through Ramot, the University’s technology transfer company. The company’s CEO is Gil Hakim, while the scientific development is led by Dr. Tamar Harel-Adar and her team.
“They managed to get us to the stage of regulatory approvals so quickly — and that’s amazing,” says Prof. Dvir.
Gil Hakim, CEO of Matricelf , concludes: “This milestone marks the shift from pioneering research to patient treatment. For the first time, we are translating years of successful preclinical work into a procedure for people living with paralysis. Our approach, using each patient’s own cells to engineer a new spinal cord, eliminates key safety risks and positions Matricelf at the forefront of regenerative medicine. If successful, this therapy has the potential to define a new standard of care in spinal cord repair, addressing a multi-billion-dollar market with no effective solutions today. This first procedure is more than a scientific breakthrough, it is a value-inflection point for Matricelf and a step toward transforming an area of medicine long considered untreatable. We are proud that Israel is leading this global effort and are fully committed to bringing this innovation to patients worldwide.”
Diana Bletter’s August 21, 2025 article for The Times of Israel (h/t August 21, 2025 Google alert) covers much of the same ground as the press release but there are some new details, Note: Links have been removed,
…
Prof. Tal Dvir, head of the Sagol Center for Regenerative Biotechnology and the Nanotechnology Center at Tel Aviv University, said his research team is now able to engineer a spinal cord that functions exactly like a natural one by implanting 3D-engineered tissue into the damaged area.
Fusion then occurs between the new tissue and the healthy areas above and below the injury that will end the paralysis.
…
The upcoming spinal cord implant surgery marks the next stage in a process that began about three years ago, when Dvir’s lab at Tel Aviv University succeeded in engineering a personalized 3D spinal cord in the laboratory.
The groundbreaking findings, published in the prestigious journal Advanced Science, demonstrated for the first time ever that mice suffering from chronic paralysis that were treated with these engineered implants started to walk — and even scamper — again.
The success rate with the engineered spinal cord was 80 percent for mice with chronic paralysis. Among those with recent or short-term paralysis, 100% of the mice walked.
…
Patients remain paralyzed because neurons do not renew
Around the world, there are over 15 million people who have suffered spinal cord injuries. Professionals can help stabilize the injury but not much else.
Dvir said that as a result, the damage only worsens. Over time, the damaged area becomes scar tissue.
“The patient remains paralyzed below the site of injury,” he said. “If the injury is in the neck, all four limbs may be paralyzed. If in the lower back, the legs will not move, and so on.”
Spinal cord injuries are one of the very few injuries in the human body that are not impacted by natural regenerative ability, Dvir explained.
“The neurons do not divide and do not renew themselves,” he said. “These cells are not like skin cells, which can heal after injury, but are more like heart cells: Once damaged, the body cannot repair them.”
“The spinal cord is composed of nerve cells that transmit electrical signals from the brain to all parts of the body,” Dvir said. “The decision is made in the brain, the electrical signal passes through the spinal cord, and from there, neurons activate the muscles throughout the body.”
When the spinal cord is severed due to trauma, such as a car accident, a fall, or a combat injury, this chain is broken.
“Think of an electrical cable that has been cut,” Dvir said. “When the two ends no longer touch, the electrical signal cannot pass. The cable will not transmit electricity, and the person cannot transmit the signal beyond the injury.”
Dvir’s team aims to fix that.
Implanting an engineered human spinal cord
Dvir said that the researchers start the process with a small biopsy from the belly.
They then take these blood cells and perform a process known as reprogramming — genetic engineering that transforms the cells into embryonic stem cell-like cells, capable of developing into any cell type in the body.
In the next step, the scientists take fatty tissue from the patient, extract key components such as collagens and sugars, and build a customized hydrogel. The embryonic stem cell-like cells are placed in this gel, and the embryonic development of a spinal cord is mimicked.
This spinal cord will then be transplanted into the human body, restoring the body’s abilities.
…
I have a link to Dvir’s company, Matricelf and a link to and a citation to the Dvir team’s 2022 study,
One more note, there is other work devoted to enable paralyzed people to walk again such as the Walk Again Project (Wikipedia entry), Note: Links have been removed,
Walk Again Project is an international, non-profit consortium led by Miguel Nicolelis, created in 2009 in a partnership between Duke University and the IINN/ELS [International Institute for Neurosciences of Natal – Edmond and Lily Safra or Instituto Internacional de Neurociências Edmond e Lily Safra; (INN-ELS)], where researchers come together to find neuro-rehabilitation treatments for spinal cord injuries,[1][2][3] which pioneered the development and use of the brain–machine interface, including its non-invasive version,[4] with an EEG.[5]
The work you see in the above is being displayed at the 2025 Venice Architecture Biennale or Biennale Architettura 2025; 19th International Architecture Exhibition being held in Venice, 10.05 – 23.11 2025 (May 10 – November 23, 2025). Note: Links have been removed.
ETH researchers present a living material consisting of a hydrogel and cyanobacteria embedded in it.
The photosynthetic bacteria extract CO2 from the atmosphere and convert it into biomass and carbonate-containing minerals.
The 3D-printable building material is intended to help reduce the carbon footprint of buildings and infrastructure in the future.
At the Venice Biennale and the Triennale in Milan, two exhibits explore how the living material could be used in architecture.
The idea seems futuristic: At ETH Zurich, various disciplines are working together to combine conventional materials with bacteria, algae and fungi. The common goal: to create living materials that acquire useful properties thanks to the metabolism of microorganisms – “such as the ability to bind CO2 from the air by means of photosynthesis,” says Mark Tibbitt, Professor of Macromolecular Engineering at ETH Zurich.
An interdisciplinary research team led by Tibbitt has now turned this vision into reality: it has stably incorporated photosynthetic bacteria – known as cyanobacteria – into a printable gel and developed a material that is alive, grows and actively removes carbon from the air. The researchers recently presented their “photosynthetic living material” in a study in the journal Nature Communications.
Key characteristic: Dual carbon sequestration
The material can be shaped using 3D printing and only requires sunlight and artificial seawater with readily available nutrients in addition to CO2 to grow. “As a building material, it could help to store CO2 directly in buildings in the future,” says Tibbitt, who co-initiated the research into living materials at ETH Zurich.
The special thing about it: the living material absorbs much more CO2 than it binds through organic growth. “This is because the material can store carbon not only in biomass, but also in the form of minerals – a special property of these cyanobacteria,” reveals Tibbitt.
Yifan Cui, one of the two lead authors of the study, explains: “Cyanobacteria are among the oldest life forms in the world. They are highly efficient at photosynthesis and can utilise even the weakest light to produce biomass from CO2 and water”.
At the same time, the bacteria change their chemical environment outside the cell as a result of photosynthesis, so that solid carbonates (such as lime) precipitate. These minerals represent an additional carbon sink and – in contrast to biomass – store CO2 in a more stable form.
Cyanobacteria as master builders
“We utilise this ability specifically in our material,” says Cui, who is a doctoral student in Tibbitt’s research group. A practical side effect: the minerals are deposited inside the material and reinforce it mechanically. In this way, the cyanobacteria slowly harden the initially soft structures.
Laboratory tests showed that the material continuously binds CO₂ over a period of 400 days, most of it in mineral form – around 26 milligrams of CO2 per gram of material. This is significantly more than many biological approaches and comparable to the chemical mineralisation of recycled concrete (around 7 mg CO2 per gram).
Hydrogel as a habitat
The carrier material that harbours the living cells is a hydrogel – a gel made of cross-linked polymers with a high water content. Tibbitt’s team selected the polymer network so that it can transport light, CO2, water and nutrients and allows the cells to spread evenly inside without leaving the material.
To ensure that the cyanobacteria live as long as possible and remain efficient, the researchers have also optimised the geometry of the structures using 3D printing processes to increase the surface area, increase light penetration and promote the flow of nutrients.
Co-first author Dalia Dranseike: “In this way, we created structures that enable light penetration and passively distribute nutrient fluid throughout the body by capillary forces.” Thanks to this design, the encapsulated cyanobacteria lived productively for more than a year, the materials researcher in Tibbitt’s team is pleased to report.
Infrastructure as a carbon sink
The researchers see their living material as a low-energy and environmentally friendly approach that can bind CO2 from the atmosphere and supplement existing chemical processes for carbon sequestration. “In the future, we want to investigate how the material can be used as a coating for building façades to bind CO2 throughout the entire life cycle of a building,” Tibbitt looks ahead.
There is still a long way to go – but colleagues from the field of architecture have already taken up the concept and realised initial interpretations in an experimental way.
Two installations in Venice and Milan
Thanks to ETH doctoral student Andrea Shin Ling, basic research from the ETH laboratories has made it onto the big stage at the Architecture Biennale in Venice. “It was particularly challenging to scale up the production process from laboratory format to room dimensions,” says the architect and bio-designer, who is also involved in this study.
Ling is doing her doctorate at ETH Professor Benjamin Dillenburger’s Chair of Digital Building Technologies [sic]. In her dissertation, she developed a platform for biofabrication that can print living structures containing functional cyanobacteria on an architectural scale.
For the Picoplanktonics installation in the Canada Pavilion, the project team used the printed structures as living building blocks to construct two tree-trunk-like objects, the largest around three metres high. Thanks to the cyanobacteria, these can each bind up to 18 kg of CO2 per year – about as much as a 20-year-old pine tree in the temperate zone.
“The installation is an experiment – we have adapted the Canada Pavilion so that it provides enough light, humidity and warmth for the cyanobacteria to thrive and then we watch how they behave,” says Ling. This is a commitment: The team monitors and maintains the installation on site – daily. Until 23 November [2025].
At the 24th Triennale di Milano, Dafne’s Skin is investigating the potential of living materials for future building envelopes. On a structure covered with wooden shingles, microorganisms form a deep green patina that changes the wood over time: A sign of decay becomes an active design element that binds CO2 and emphasises the aesthetics of microbial processes. Dafne’s Skin is a collaboration between MAEID Studio and Dalia Dranseike. It is part of the exhibition “We the Bacteria: Notes Toward Biotic Architecture” and runs until 9 November [2025].
The photosynthetic living material was created thanks to an interdisciplinary collaboration within the framework of ALIVE (Advanced Engineering with Living Materials). The ETH Zurich initiative promotes collaboration between researchers from different disciplines in order to develop new living materials for a wide range of applications.
Before exploring the Canadian connection a little further, here’s a link to and a citation for the paper,
Dual carbon sequestration with photosynthetic living materials by Dalia Dranseike, Yifan Cui, Andrea S. Ling, Felix Donat, Stéphane Bernhard, Margherita Bernero, Akhil Areeckal, Marco Lazic, Xiao-Hua Qin, John S. Oakey, Benjamin Dillenburger, André R. Studart & Mark W. Tibbitt. Nature Communications volume 16, Article number: 3832 (2025) DOI: https://doi.org/10.1038/s41467-025-58761-y Published: 23 April 2025
On the occasion of Canada’s participation in the 19th International Architecture Exhibition – La Biennale di Venezia, the Canada Council for the Arts present Picoplanktonics at the Canada Pavilion, from May 10 to November 23, 2025.
Amidst the ongoing global climate crisis, the Living Room Collective has developed a ground-breaking exhibition that showcases the potential for collaboration between humans and nature. Comprised of 3D printed structures that contain live cyanobacteria capable of carbon sequestration, Picoplanktonics is an exploration of our potential to co-operate with living systems by co-constructing spaces that remediate the planet rather than exploit it.
The Living Room Collective’s exhibition is the culmination of four years of collaborative research by Andrea Shin Ling and various interdisciplinary contributors. It is focused on harnessing the design principles of living systems to develop sustainable, intelligent and resilient materials and technologies for the future. By leveraging ancient biological processes alongside emergent technologies, it proposes designing environments under an ecology-first ethos.
“The Canada Council for the Arts is delighted to unveil Picoplanktonics by the Living Room Collective at the 19th International Architecture Exhibition – La Biennale di Venezia. Through the lens of architecture, this year’s Canadian exhibition brings technological innovation and ecological stewardship together. It is a unique exhibition, sure to inspire global audiences and to ignite important conversations, about how our built environment might better house and use natural systems for a more sustainable future.”
– Michelle Chawla, Director and CEO, Canada Council for the Arts
When visitors enter the Canada Pavilion, they will encounter 3D printed structures that were originally fabricated in an ETH Zürich laboratory. These are the largest living material structures produced using a first-of-its-kind biofabrication platform capable of printing living structures at an architectural scale. The unique Picoplanktonics experience stems from adapting the Canada Pavilion to provide enough light, moisture, and warmth for the living cyanobacteria within the structures to grow, thrive and change. For the duration of the exhibition, caretakers will be onsite tending to the structures, emphasizing care and stewardship as essential elements of the design.
As global carbon emissions continue to rise to untenable levels, Picoplanktonics presents a vision of how a regenerative system of construction could operate. It is an ongoing experiment centered on leveraging the reciprocal relationship between living structures, the built environment, and humans. In this way, the Living Room Collective is rethinking building principles and prioritizing ecological resilience beyond human species survival.
…
“Picoplanktonics marks four years of research at ETH Zürich with international collaborators in material science, biology, robotics, and computational design. As we move these living prototypes into the Canada Pavilion, we are thrilled to invite the public into this open experiment and reveal all phases of the material’s life, including growth, sickness, and death, while collectively imagining a regenerative design approach that seeks planetary remediation.”
–Andrea Shin Ling, The Living Room Collective
The Living Room Collective
The Living Room Collective is a group of architects, scientists, artists and educators who work at the intersection of architecture, biology and digital fabrication technologies—led by Canadian architect and biodesigner Andrea Shin Ling. Alongside core team members Nicholas Hoban, Vincent Hui and Clayton Lee, the collective seeks to move society away from exploitative systems of production to regenerative ones by inventing design methods and processes that center on natural systems.
They see the Biennale Architettura 2025 as a platform to generate national and international conversations that ask: How does one fabricate a biological architecture? What are the conditions of stewardship? What are the strategies to instigate this at scale, regionally and globally?
Andrea Shin Ling is an architect and biodesigner who works at the intersection of design, digital fabrication and biology. Her work focuses on how the critical application of biologically and computationally mediated design processes can move society away from exploitative systems of production to regenerative ones. She is the 2020 S+T+ARTS Grand Prize winner for her work as Ginkgo Bioworks’ creative resident designing the decay of artifacts in order to access material circularity. Andrea is a founder of designGUILD, a Toronto-based art collective, and was a researcher in the Mediated Matter group at the MIT Media Lab, where she worked on AguahojaI, a 3D-printed bio-material pavilion. She is currently a doctoral fellow at the Chair of Digital Building Technologies at ETH Zurich.
Nicholas Hoban is a computational designer, fabricator and educator. He works at the intersection of computational design, robotics, construction and simulation in pedagogy, research and practice. Nicholas is the director of applied technologies at the John H. Daniels Faculty of Architecture [University of Toronto], Landscape, and Design and a lecturer within the Daniels technology specialist program, leading various research and teaching labs while developing curriculum for studios and seminars on advanced fabrication and robotics within architecture. His research focuses on the application of robotics within fabrication and construction and on how we can solve critical problems in geometry through integrated processes. Nicholas was a lead fabricator and computational designer for two previous Venice Biennales: for the 2014 Canadian Pavilion for Lateral Office’s Arctic Adaptations and for the 2016 Swiss Pavilion for Christian Kerez’s Incidental Space.
Vincent Hui is a distinguished professor at Toronto Metropolitan University’s Department of Architectural Science, imparting knowledge across diverse domains from design studios to digital tools. His pedagogical excellence has earned him multiple teaching accolades, as he delves into the intersections of architecture, fabrication and allied disciplines. With over 25 years of experience, his extensive publication portfolio focuses on design pedagogy, simulation, prototyping and technological convergence, complemented by a rich body of creative work showcased globally. Collaborating with esteemed organizations such as the Royal Architectural Institute of Canada (RAIC), the Ontario Association of Architects (OAA) and the Canadian Architecture Students’ Association (CASA), Vincent endeavours to empower the next generation of designers, navigating emergent shifts in praxis. Committed to bridging academia and industry, he advocates for experiential learning initiatives and outreach endeavours for aspiring designers. His remarkable contributions have culminated in his induction into the esteemed RAIC College of Fellows.
Clayton Lee is a curator, producer and performance artist. He is currently the director (artistic) of the Fierce Festival, in Birmingham, UK. He was previously the director of the Rhubarb Festival, Canada’s longest-running festival of new and experimental performance, at Buddies in Bad Times Theatre. Clayton has also worked as creative producer on Jess Dobkin’s projects, including For What It’s Worth, her commission at the Wellcome Collection, in London, UK; as curatorial associate at the Luminato Festival; and as managing producer of the CanadaHub at the Edinburgh Festival Fringe. His performance projects have been presented in venues across Canada, the United States, the United Kingdom and New Zealand. He was one of the Art Gallery of Ontario’s 2023 artists-in-residence.
…
There are still a few months left if you want to attend. Bon Voyage!
In the relentless quest to develop materials that combine flexibility, durability, and functionality, a novel breakthrough in hydrogel technology shines a promising light on the future of wearable electronics and soft robotics. Engineers and material scientists from Southwest Forestry University in China have synthesized an ultra-robust hydrogel utilizing bamboo cellulose-based carbon nanomaterials (C-BCN), a development that could set new standards in the performance of flexible devices.
Hydrogels have long been recognized for their potential in various applications, including tissue engineering, drug delivery, and wearable electronics. However, traditional hydrogels often lack the mechanical strength and durability needed for demanding applications. Now, researchers from Southwest Forestry University in China have developed an innovative solution using bamboo cellulose-based carbon nanomaterials (C-BCN) to create an ultra-robust hydrogel with remarkable properties.
The study, published in the Journal of Bioresources and Bioproducts, details the process of creating the hydrogel. The researchers treated bamboo fibers with phthalic anhydride and then carbonized them to produce C-BCN. These nanomaterials were integrated into an acrylamide precursor solution to synthesize a conductive hydrogel (PAM-C-BCN) with exceptional mechanical properties. The hydrogel exhibited a fracture strength of 363 kPa, an elongation of 2,254%, a fracture energy of 30 kJ/m², and a toughness of 3.04 MJ/m³. Additionally, the hydrogel demonstrated high adhesion (up to 7.5 kPa on pigskin) and conductivity (0.21 S/m).
The researchers found that the C-BCN significantly enhanced the mechanical resilience and energy dissipation capabilities of the hydrogel. The nanomaterials formed strong interfacial interactions with the polyacrylamide (PAM) matrix, creating a densely interpenetrated network. This structure not only improved the hydrogel’s mechanical properties but also provided excellent fatigue resistance and adhesion. The hydrogel’s ability to restrain crack propagation was particularly noteworthy, making it highly suitable for applications requiring high mechanical performance.
The study’s findings have significant implications for the development of flexible electronics and wearable devices. The PAM-C-BCN hydrogel’s excellent mechanical properties, combined with its high conductivity and adhesion, make it a promising material for applications such as electronic skin, soft robotics, and strain sensors. The researchers suggest that further optimization of the C-BCN production process could enhance the hydrogel’s performance even further.
An April 3, 2025 news item on ScienceDaily announces work that promises to bring researchers closer to ending nanoparticle cosmetic testing on animals,
A research team from TU Graz [Austria[ and the Vellore Institute of Technology in India is developing a 3D-printed skin imitation equipped with living cells in order to test nanoparticles from cosmetics without animal testing.
Directive 2010/63/EU laid down restrictions on animal testing for the testing of cosmetics and their ingredients throughout the EU. Therefore, there is an intense search for alternatives to test the absorption and toxicity of nanoparticles from cosmetics such as sun creams.
“The hydrogels for our skin imitation from the 3D printer have to fulfil a number of requirements,” says Karin Stana Kleinschek from the Institute of Chemistry and Technology of Biobased Systems. “The hydrogels must be able to interact with living skin cells. These cells not only have to survive, but also have to be able to grow and multiply.” The starting point for stable and 3D-printable structures are hydrogel formulations developed at TU Graz. Hydrogels are characterised by their high-water content, which creates ideal conditions for the integration and growth of cells. However, the high-water content also requires methods for mechanical and chemical stabilisation of the 3D prints.
TU Graz is working intensively on cross-linking methods for stabilisation. Ideally, following nature’s example, the cross-linking takes place under very mild conditions and without the use of cytotoxic chemicals. After successful stabilisation, the cooperation partners in India test the resistance and toxicity of the 3D prints in cell culture. Only when skin cells in the hydrogel survive in cell culture for two to three weeks and develop skin tissue can we speak of a skin imitation. This skin imitation can then be used for further cell tests on cosmetics.
Successful tests
The first tests of 3D-printed hydrogels in cell culture were very successful. The cross-linked materials are non-cytotoxic and mechanically stable. “In the next step, the 3D-printed models (skin imitations) will be used to test nanoparticles,” says Karin Stana Kleinschek. “This is a success for the complementary research at TU Graz and VIT. Our many years of expertise in the field of material research for tissue imitations and VIT’s expertise in molecular and cell biology have complemented each other perfectly. We are now working together to further optimise the hydrogel formulations and validate their usefulness as a substitute for animal experiments.”
The original headline for the University of Oxford press release was “Batteries for miniature bio-integrated devices and robotics” but it’s not clear to me what they mean by robotics (soft robots? robotic prostheses? something else?).
University of Oxford researchers have made a significant step towards realising miniature, soft batteries for use in a variety of biomedical applications, including the defibrillation and pacing of heart tissues. The work has been published today [October 25, 2024] in the journal Nature Chemical Engineering.
…
An October 28, 2024 University of Oxford press release (also on EurekAlert but published October 25, 2024), which originated the lightly edited news item and posting on EurekAlert, provides more technical detail about this advance, Note: Links have been removed,
The development of tiny smart devices, smaller than a few cubic millimeters, demands equally small power sources. For minimally invasive biomedical devices that interact with biological tissues, these power sources must be fabricated from soft materials. Ideally, these should also have features such as high capacity, biocompatibility and biodegradability, triggerable activation, and the ability to be controlled remotely. To date, there has been no battery that can fulfil these requirements all at once.
To address these requirements, researchers from the University of Oxford’s Department of Chemistry and Department of Pharmacology have developed a miniature, soft lithium-ion battery constructed from biocompatible hydrogel droplets. Surfactant-supported assembly (assembly aided by soap-like molecules), a technique reported by the same group last year in the journal Nature (DOI: 10.1038/s41586-023-06295-y), is used to connect three microscale droplets of 10 nanolitres volume. Different lithium-ion particles contained in each of the two ends then generate the output energy.
‘Our droplet battery is light-activated, rechargeable, and biodegradable after use. To date, it is the smallest hydrogel lithium-ion battery and has a superior energy density’ said Dr Yujia Zhang (Department of Chemistry, University of Oxford), the lead researcher for the study and a starting Assistant Professor at the École Polytechnique Fédérale de Lausanne. ‘We used the droplet battery to power the movement of charged molecules between synthetic cells and to control the beating and defibrillation of mouse hearts. By including magnetic particles to control movement, the battery can also function as a mobile energy carrier.’
Proof-of-concept heart treatments were carried out in the laboratory of Professor Ming Lei (Department of Pharmacology), a senior electrophysiologist in cardiac arrhythmias. He said: ‘Cardiac arrhythmia is a leading cause of death worldwide. Our proof-of-concept application in animal models demonstrates an exciting new avenue of wireless and biodegradable devices for the management of arrhythmias.’
Professor Hagan Bayley (Department of Chemistry), the research group leader for the study, said: ‘The tiny soft lithium-ion battery is the most sophisticated in a series of microscale power packs developed by Dr Zhang and points to a fantastic future for biocompatible electronic devices that can operate under physiological conditions.’
The researchers have filed a patent application through Oxford University Innovation. They envisage that the tiny versatile battery, particularly relevant to small-scale robots for bioapplications, will open up new possibilities in various areas including clinical medicine.
Here’s a link to and a citation for the paper,
A microscale soft lithium-ion battery for tissue stimulation by Yujia Zhang, Tianyi Sun, Xingyun Yang, Linna Zhou, Cheryl M. J. Tan, Ming Lei & Hagan Bayley. Nature Chemical Engineering volume 1, pages 691–701 (2024) DOI: https://doi.org/10.1038/s44286-024-00136-z Published online: 25 October 2024 Issue Date: November 2024
This paper is open access.
Now, I want to highlight a few items from the paper’s introduction, Note: Links have been removed,
The miniaturization of electronic devices is a burgeoning area of research1,2,3. Therefore, the development of tiny batteries to power these devices is of critical importance, and techniques such as three-dimensional (3D) printing4,5,6 and micro-origami assembly7 [emphases mine] are beginning to have an impact. For minimally invasive applications in biomedicine, batteries are also preferred to be soft, biocompatible and biodegradable, with additional functionality and responsiveness, such as triggerable activation and remote-controlled mobility8. However, at present, such a multifunctional microscale soft battery is not available. Although hydrogel-based lithium-ion (Li-ion) batteries demonstrate some of these features9,10,11,12, none currently exhibits microscale fabrication of the battery architecture, in terms of self-assembled integration of hydrogel-based cathode, separator and anode at the submillimeter level. Manual assembly of precrosslinked compartments11 or multistep deposition and crosslinking4 is necessary to avoid the mixing of materials from different compartments at the pregel (liquid) state or during the gelation process. This limitation not only makes it difficult to shrink hydrogel-based functional architectures but also hinders the implementation of high-density energy storage.
Toward that end, Zhang et al. have reported a miniaturized ionic power source by depositing lipid-supported networks of nanoliter hydrogel droplets13. The power source mimics the electrical eel [emphasis mine] by using internal ion gradients to generate ionic current14, and can induce neuronal modulation. However, the ionic power source has several limitations [emphasis mine] that should be addressed. First, the stored salt gradient produces less power than conventional Li-ion batteries, and the device cannot be fully recharged. Second, activation of the power source relies on temperature-triggered gelation and oil for buffer exchange, which is a demanding requirement. Third, the functionality of the power source is limited to the generation of ionic output, leaving the full versatility of synthetic tissues unexploited15,16,17. Last, but not least, while the power source can modulate the activity of neural microtissues, organ-level stimulation necessitates a higher and more stable output performance in physiological environments18.
Here, we present a miniature, soft, rechargeable Li-ion droplet battery (LiDB) made by depositing self-assembling [emphasis mine], nanoliter, lipid-supported, silk hydrogel droplets. The tiny hydrogel compartmentalization produces a superior energy density. The battery is switched on by ultraviolet (UV) light, which crosslinks the hydrogel and breaks the lipid barrier between droplets. The droplets are soft, biocompatible and biodegradable. The LiDBs can power charge molecule translocation between synthetic cells, defibrillate mouse hearts with ventricular arrhythmias and pace heart rhythms. Further, the LiDB can be translocated from one site to another magnetically.
This team has integrated a number of cutting edge (I think you can still call them that) techniques such as 3D printing and origami along with inspiration from electric eels (biomimicry) for using light as a power source. .Finally, there’s self-assembly or, as it’s sometimes known, bottom-up engineering, just like nature.
This work still needs to be tested in human clinical trials but taking that into account: Bravo to the researchers!
The ideal material for interfacing electronics with living tissue is soft, stretchable, and just as water-loving as the tissue itself–in short, a hydrogel. Semiconductors, the key materials for bioelectronics such as pacemakers, biosensors, and drug delivery devices, on the other hand, are rigid, brittle, and water-hating, impossible to dissolve in the way hydrogels have traditionally been built. Scientists have now solved this challenge that has long stymied researchers, reimagining the process of creating hydrogels to build a powerful semiconductor in hydrogel form. The result is a bluish gel that flutters like a sea jelly in water but retains the immense semiconductive ability needed to transmit information between living tissue and machine.
A paper published today in Science from the UChicago Pritzker School of Molecular Engineering (PME) has solved this challenge that has long stymied researchers, reimagining the process of creating hydrogels to build a powerful semiconductor in hydrogel form. Led by Asst. Prof. Sihong Wang’s research group, the result is a bluish gel that flutters like a sea jelly in water but retains the immense semiconductive ability needed to transmit information between living tissue and machine.
The material demonstrated tissue-level moduli as soft as 81 kPa, stretchability of 150% strain, and charge-carrier mobility up to 1.4 cm2 V-1 s-1. This means their material—both semiconductor and hydrogel at the same time—ticks all the boxes for an ideal bioelectronic interface.
“When making implantable bioelectronic devices, one challenge you must address is to make a device with tissue-like mechanical properties,” said Yahao Dai, the first author of the new paper. “That way, when it gets directly interfaced with the tissue, they can deform together and also form a very intimate bio-interface.”
Although the paper mainly focused on the challenges facing implanted medical devices such as biochemical sensors and pacemakers, Dai said the material also has many potential non-surgical applications, like better readings off the skin or improved care for wounds.
“It has very soft mechanical properties and a large degree of hydration similar to living tissue,” said UChicago PME Asst. Prof. Sihong Wang. “Hydrogel is also very porous, so it allows the efficient diffusion transport of different kinds of nutrition and chemicals. All these traits combine to make hydrogel probably the most useful material for tissue engineering and drug delivery.”
‘Let’s change our perspective’
The typical way of making a hydrogel is to take a material, dissolve it in water, and add the gelation chemicals to puff the new liquid into a gel form. Some materials simply dissolve in water, others require researchers to tinker and chemically modify the process, but the core mechanism is the same: No water, no hydrogel.
Semiconductors, however, don’t normally dissolve in water. Rather than find new, time-consuming means of trying to force the process, the UChicago PME team re-examined the question.
“We started to think, ‘Okay, let’s change our perspective,’ and we came up with a solvent exchange process,” Dai said.
Instead of dissolving the semiconductors in water, they dissolved them in an organic solvent that is miscible with water. They then prepared a gel from the dissolved semiconductors and hydrogel precursors. Their gel initially was an organogel, not a hydrogel.
“To eventually turn it into a hydrogel, we then immersed the whole material system into the water to let the organic solvent dissolve out and let the water come in,” Dai said.
An important benefit of such a solvent-exchange-based method is its broad applicability to different types of polymer semiconductors with different functions.
‘One plus one is greater than two’
The hydrogel semiconductor, which the team has patented and is commercializing through UChicago’s Polsky Center for Entrepreneurship and Innovation, is not merging a semiconductor with a hydrogel. It’s one material that is both semiconductor and hydrogel at the same time.
“It’s just one piece that has both semiconducting properties and hydrogel design, meaning that this whole piece is just like any other hydrogel,” Wang said.
Unlike any other hydrogel, however, the new material actually improved biological functions in two areas, creating better results than either hydrogel or semiconductor could accomplish on their own.
First, having a very soft material bond directly with tissue reduces the immune responses and inflammation typically triggered when a medical device is implanted.
Second, because hydrogels are so porous, the new material enables elevated biosensing response and stronger photo-modulation effects. With biomolecules being able to diffuse into the film to have volumetric interactions, the interaction sites for biomarkers-under-detection are significantly increased, which gives rise to higher sensitivity. Besides sensing, the responses to light for therapeutic functions at tissue surfaces also get increased from the more efficient transport of redox-active species. This benefits functions such as light-operated pacemakers or wound dressing that can be more efficiently heated with a flick of light to help speed healing.
“It’s a ‘one plus one is greater than two’ kind of combination,” Wang joked.
Researchers in the lab of UChicago Pritzker School of Engineering Asst. Prof. Sihong Wang (right), including PhD student Yahao Dai (left), have developed a hydrogel that retains the semiconductive ability needed to transmit information between living tissue and machine, which can be used both in implantable medical devices and non-surgical applications. (Photo by John Zich)
Here’s a link to and a citation for the paper,
Soft hydrogel semiconductors with augmented biointeractive functions by Yahao Dai, Shinya Wai, Pengju Li, Naisong Shan, Zhiqiang Cao, Yang Li, Yunfei Wang, Youdi Liu, Wei Liu, Kan Tang, Yuzi Liu, Muchuan Hua, Songsong Li, Nan Li, Shivani Chatterji, H. Christopher Fry, Sean Lee, Cheng Zhang, Max Weires, Sean Sutyak, Jiuyun Shi, Chenhui Zhu, Jie Xu, Xiaodan Gu, Bozhi Tian, and Sihong Wang. Science 24 Oct 2024 Vol 386, Issue 6720 pp. 431-439 DOI: 10.1126/science.adp9314
