Tag Archives: tissue engineering

Tractor beams for artificial cells

This particular piece has videos of cells moving around. I won’t be including all of them but they are weirdly fascinating. First, a May 14, 2018 news item on Nanowerk announces the latest in tractor beam news from the Imperial College London (ICL; UK),

Researchers have used lasers to connect, arrange and merge artificial cells, paving the way for networks of artificial cells that act like tissues.

The team say that by altering artificial cell membranes they can now get the cells to stick together like ‘stickle bricks’ – allowing them to be arranged into whole new structures.

Biological cells can perform complex functions, but are difficult to controllably engineer.

Artificial cells, however, can in principle be made to order. Now, researchers from Imperial College London and Loughborough University have demonstrated a new level of complexity with artificial cells by arranging them into basic tissue structures with different types of connectivity.

These structures could be used to perform functions like initiating chemical reactions or moving chemicals around networks of artificial and biological cells. This could be useful in carrying out chemical reactions in ultra-small volumes, in studying the mechanisms through which cells communicate with one another, and in the development of a new generation of smart biomaterials.

A May 14, 2018 ICL press release by Hayley Dunning , which originated the news item, provides more detail,

Cells are the basic units of biology, which are capable of working together as a collective when arranged into tissues. In order to do this, cells must be connected and be capable of exchanging materials with one another.

The team were able to link up artificial cells into a range of new architectures, the results of which are published today in Nature Communications.

The artificial cells have a membrane-like layer as their shell, which the researchers engineered to ‘stick’ to each other. In order to get the cells to come close enough, the team first had to manipulate the cells with ‘optical tweezers’ that act like mini ‘tractor beams’ dragging and dropping cells into any position. Once connected in this way the cells can be moved as one unit.

Lead researcher Dr Yuval Elani, an EPSRC Research Fellow from the Department of Chemistry at Imperial, said: “Artificial cell membranes usually bounce off each other like rubber balls. By altering the biophysics of the membranes in our cells, we got them instead to stick to each other like stickle bricks.

“With this, we were able to form networks of cells connected by ‘biojunctions’. By reinserting biological components such as proteins in the membrane, we could get the cells to communicate and exchange material with one another. This mimics what is seen in nature, so it’s a great step forward in creating biological-like artificial cell tissues.”

Building up complexity

The team were also able to engineer a ‘tether’ between two cells. Here the membranes are not stuck together, but a tendril of membrane material links them so that they can be moved together.

Once they had perfected the cell-sticking process, the team were able to build up more complex arrangements. These include lines of cells, 2D shapes like squares, and 3D shapes like pyramids. Once the cells are stuck together, they can be rearranged, and also pulled by the laser beam as an ensemble

Finally, the team were also able to connect two cells, and then make them merge into one larger cell. This was achieved by coating the membranes with gold nanoparticles.

When the laser beam at the heart of the ‘optical tweezer’ technology was concentrated at the junction between the two cells, the nanoparticles resonated, breaking the membranes at that point. The membrane then reforms as a whole.

Merging cells in this way allowed whatever chemicals they were carrying to mix within the new, larger cell, kicking off chemical reactions. This could be useful, for example, for delivering materials such as drugs into cells, and in changing the composition of cells in real time, getting them to adopt new functions.

Professor Oscar Ces, also from the Department of Chemistry at Imperial, said: “Connecting artificial cells together is a valuable technology in the wider toolkit we are assembling for creating these biological systems using bottom-up approaches.

“We can now start to scale up basic cell technologies into larger tissue-scale networks, with precise control over the kind of architecture we create.”

Here’s one of the videos that has been embedded with ICL press release,

You can see the whole series if you go to the May 14, 2018 ICL press release.

Here’s a link to and a citation for the paper,

Sculpting and fusing biomimetic vesicle networks using optical tweezers by Guido Bolognesi, Mark S. Friddin, Ali Salehi-Reyhani, Nathan E. Barlow, Nicholas J. Brooks, Oscar Ces, & Yuval Elani. Nature Communicationsvolume 9, Article number: 1882 (2018) doi:10.1038/s41467-018-04282-w Published: 14 May 2018

This paper is open access.

Robotics where and how you don’t expect them: a wearable robot and a robot implant for regeneration

Generally I  expect robots to be machines that are external to my body but recently there were two news bits about some different approaches. First, the wearable robot.

A robot that supports your hip

A January 10, 2018 news item on ScienceDaily describes research into muscles that can be worn,

Scientists are one step closer to artificial muscles. Orthotics have come a long way since their initial wood and strap designs, yet innovation lapsed when it came to compensating for muscle power — until now.

A collaborative research team has designed a wearable robot to support a person’s hip joint while walking. The team, led by Minoru Hashimoto, a professor of textile science and technology at Shinshu University in Japan, published the details of their prototype in Smart Materials and Structures, a journal published by the Institute of Physics.

A January 9, 2018 Shinshu University press release on EurekAlert, which originated the news item, provides more detail,

“With a rapidly aging society, an increasing number of elderly people require care after suffering from stroke, and other-age related disabilities. Various technologies, devices, and robots are emerging to aid caretakers,” wrote Hashimoto, noting that several technologies meant to assist a person with walking are often cumbersome to the user. “[In our] current study, [we] sought to develop a lightweight, soft, wearable assist wear for supporting activities of daily life for older people with weakened muscles and those with mobility issues.”

The wearable system consists of plasticized polyvinyl chloride (PVC) gel, mesh electrodes, and applied voltage. The mesh electrodes sandwich the gel, and when voltage is applied, the gel flexes and contracts, like a muscle. It’s a wearable actuator, the mechanism that causes movement.

“We thought that the electrical mechanical properties of the PVC gel could be used for robotic artificial muscles, so we started researching the PVC gel,” said Hashimoto. “The ability to add voltage to PVC gel is especially attractive for high speed movement, and the gel moves with high speed with just a few hundred volts.”

In a preliminary evaluation, a stroke patient with some paralysis on one side of his body walked with and without the wearable system.

“We found that the assist wear enabled natural movement, increasing step length and decreasing muscular activity during straight line walking,” wrote Hashimoto. The researchers also found that adjusting the charge could change the level of assistance the actuator provides.

The robotic system earned first place in demonstrations with their multilayer PVC gel artificial muscle at the, “24th International Symposium on Smart Structures and Materials & Nondestructive Evaluation and Health Monitoring” for SPIE the international society for optics and photonics.

Next, the researchers plan to create a string actuator using the PVC gel, which could potentially lead to the development of fabric capable of providing more manageable external muscular support with ease.

Here’s a link to and a citation for the paper,

PVC gel soft actuator-based wearable assist wear for hip joint support during walking by Yi Li and Minoru Hashimoto. Smart Materials and Structures, Volume 26, Number 12 DOI: 10.1088/1361-665X/aa9315 Published 30 October 2017

© 2017 IOP Publishing Ltd

This paper is behind a paywall and I see it was published in the Fall of 2017. Either they postponed the publicity or this is the second wave. In any event, it was timely as it allowed me to post this along with the robotic research on regeneration.

Robotic implants and tissue regeneration

Boston Children’s Hospital in a January 10, 2018 news release on EurekAlert describes a new (to me) method for tissue regeneration,

An implanted, programmable medical robot can gradually lengthen tubular organs by applying traction forces — stimulating tissue growth in stunted organs without interfering with organ function or causing apparent discomfort, report researchers at Boston Children’s Hospital.

The robotic system, described today in Science Robotics, induced cell proliferation and lengthened part of the esophagus in a large animal by about 75 percent, while the animal remained awake and mobile. The researchers say the system could treat long-gap esophageal atresia, a rare birth defect in which part of the esophagus is missing, and could also be used to lengthen the small intestine in short bowel syndrome.

The most effective current operation for long-gap esophageal atresia, called the Foker process, uses sutures anchored on the patient’s back to gradually pull on the esophagus. To prevent the esophagus from tearing, patients must be paralyzed in a medically induced coma and placed on mechanical ventilation in the intensive care unit for one to four weeks. The long period of immobilization can also cause medical complications such as bone fractures and blood clots.

“This project demonstrates proof-of-concept that miniature robots can induce organ growth inside a living being for repair or replacement, while avoiding the sedation and paralysis currently required for the most difficult cases of esophageal atresia,” says Russell Jennings, MD, surgical director of the Esophageal and Airway Treatment Center at Boston Children’s Hospital, and a co-investigator on the study. “The potential uses of such robots are yet to be fully explored, but they will certainly be applied to many organs in the near future.”

The motorized robotic device is attached only to the esophagus, so would allow a patient to move freely. Covered by a smooth, biocompatible, waterproof “skin,” it includes two attachment rings, placed around the esophagus and sewn into place with sutures. A programmable control unit outside the body applies adjustable traction forces to the rings, slowly and steadily pulling the tissue in the desired direction.

The device was tested in the esophagi of pigs (five received the implant and three served as controls). The distance between the two rings (pulling the esophagus in opposite directions) was increased by small, 2.5-millimeter increments each day for 8 to 9 days. The animals were able to eat normally even with the device applying traction to its esophagus, and showed no sign of discomfort.

On day 10, the segment of esophagus had increased in length by 77 percent on average. Examination of the tissue showed a proliferation of the cells that make up the esophagus. The organ also maintained its normal diameter.

“This shows we didn’t simply stretch the esophagus — it lengthened through cell growth,” says Pierre Dupont, PhD, the study’s senior investigator and Chief of Pediatric Cardiac Bioengineering at Boston Children’s.

The research team is now starting to test the robotic system in a large animal model of short bowel syndrome. While long-gap esophageal atresia is quite rare, the prevalence of short bowel syndrome is much higher. Short bowel can be caused by necrotizing enterocolitis in the newborn, Crohn’s disease in adults, or a serious infection or cancer requiring a large segment of intestine to be removed.

“Short bowel syndrome is a devastating illness requiring patients to be fed intravenously,” says gastroenterologist Peter Ngo, MD, a coauthor on the study. “This, in turn, can lead to liver failure, sometimes requiring a liver or multivisceral (liver-intestine) transplant, outcomes that are both devastating and costly.”

The team hopes to get support to continue its tests of the device in large animal models, and eventually conduct clinical trials. They will also test other features.

“No one knows the best amount of force to apply to an organ to induce growth,” explains Dupont. “Today, in fact, we don’t even know what forces we are applying clinically. It’s all based on surgeon experience. A robotic device can figure out the best forces to apply and then apply those forces precisely.”

Here’s a link to and a citation for the paper,

In vivo tissue regeneration with robotic implants by Dana D. Damian, Karl Price, Slava Arabagi, Ignacio Berra, Zurab Machaidze, Sunil Manjila, Shogo Shimada, Assunta Fabozzo, Gustavo Arnal, David Van Story, Jeffrey D. Goldsmith, Agoston T. Agoston, Chunwoo Kim, Russell W. Jennings, Peter D. Ngo, Michael Manfredi, and Pierre E. Dupont. Science Robotics 10 Jan 2018: Vol. 3, Issue 14, eaaq0018 DOI: 10.1126/scirobotics.aaq0018

This paper is behind a paywall.

A transatlantic report highlighting the risks and opportunities associated with synthetic biology and bioengineering

I love e-Life, the open access journal where its editors noted that a submitted synthetic biology and bioengineering report was replete with US and UK experts (along with a European or two) but no expert input from other parts of the world. In response the authors added ‘transatlantic’ to the title. It was a good decision since it was too late to add any new experts if the authors planned to have their paper published in the foreseeable future.

I’ve commented many times here when panels of experts include only Canadian, US, UK, and, sometimes, European or Commonwealth (Australia/New Zealand) experts that we need to broaden our perspectives and now I can add: or at least acknowledge (e.g. transatlantic) that the perspectives taken are reflective of a rather narrow range of countries.

Now getting to the report, here’s more from a November 21, 2017 University of Cambridge press release,

Human genome editing, 3D-printed replacement organs and artificial photosynthesis – the field of bioengineering offers great promise for tackling the major challenges that face our society. But as a new article out today highlights, these developments provide both opportunities and risks in the short and long term.

Rapid developments in the field of synthetic biology and its associated tools and methods, including more widely available gene editing techniques, have substantially increased our capabilities for bioengineering – the application of principles and techniques from engineering to biological systems, often with the goal of addressing ‘real-world’ problems.

In a feature article published in the open access journal eLife, an international team of experts led by Dr Bonnie Wintle and Dr Christian R. Boehm from the Centre for the Study of Existential Risk at the University of Cambridge, capture perspectives of industry, innovators, scholars, and the security community in the UK and US on what they view as the major emerging issues in the field.

Dr Wintle says: “The growth of the bio-based economy offers the promise of addressing global environmental and societal challenges, but as our paper shows, it can also present new kinds of challenges and risks. The sector needs to proceed with caution to ensure we can reap the benefits safely and securely.”

The report is intended as a summary and launching point for policy makers across a range of sectors to further explore those issues that may be relevant to them.

Among the issues highlighted by the report as being most relevant over the next five years are:

Artificial photosynthesis and carbon capture for producing biofuels

If technical hurdles can be overcome, such developments might contribute to the future adoption of carbon capture systems, and provide sustainable sources of commodity chemicals and fuel.

Enhanced photosynthesis for agricultural productivity

Synthetic biology may hold the key to increasing yields on currently farmed land – and hence helping address food security – by enhancing photosynthesis and reducing pre-harvest losses, as well as reducing post-harvest and post-consumer waste.

Synthetic gene drives

Gene drives promote the inheritance of preferred genetic traits throughout a species, for example to prevent malaria-transmitting mosquitoes from breeding. However, this technology raises questions about whether it may alter ecosystems [emphasis mine], potentially even creating niches where a new disease-carrying species or new disease organism may take hold.

Human genome editing

Genome engineering technologies such as CRISPR/Cas9 offer the possibility to improve human lifespans and health. However, their implementation poses major ethical dilemmas. It is feasible that individuals or states with the financial and technological means may elect to provide strategic advantages to future generations.

Defence agency research in biological engineering

The areas of synthetic biology in which some defence agencies invest raise the risk of ‘dual-use’. For example, one programme intends to use insects to disseminate engineered plant viruses that confer traits to the target plants they feed on, with the aim of protecting crops from potential plant pathogens – but such technologies could plausibly also be used by others to harm targets.

In the next five to ten years, the authors identified areas of interest including:

Regenerative medicine: 3D printing body parts and tissue engineering

While this technology will undoubtedly ease suffering caused by traumatic injuries and a myriad of illnesses, reversing the decay associated with age is still fraught with ethical, social and economic concerns. Healthcare systems would rapidly become overburdened by the cost of replenishing body parts of citizens as they age and could lead new socioeconomic classes, as only those who can pay for such care themselves can extend their healthy years.

Microbiome-based therapies

The human microbiome is implicated in a large number of human disorders, from Parkinson’s to colon cancer, as well as metabolic conditions such as obesity and type 2 diabetes. Synthetic biology approaches could greatly accelerate the development of more effective microbiota-based therapeutics. However, there is a risk that DNA from genetically engineered microbes may spread to other microbiota in the human microbiome or into the wider environment.

Intersection of information security and bio-automation

Advancements in automation technology combined with faster and more reliable engineering techniques have resulted in the emergence of robotic ‘cloud labs’ where digital information is transformed into DNA then expressed in some target organisms. This opens the possibility of new kinds of information security threats, which could include tampering with digital DNA sequences leading to the production of harmful organisms, and sabotaging vaccine and drug production through attacks on critical DNA sequence databases or equipment.

Over the longer term, issues identified include:

New makers disrupt pharmaceutical markets

Community bio-labs and entrepreneurial startups are customizing and sharing methods and tools for biological experiments and engineering. Combined with open business models and open source technologies, this could herald opportunities for manufacturing therapies tailored to regional diseases that multinational pharmaceutical companies might not find profitable. But this raises concerns around the potential disruption of existing manufacturing markets and raw material supply chains as well as fears about inadequate regulation, less rigorous product quality control and misuse.

Platform technologies to address emerging disease pandemics

Emerging infectious diseases—such as recent Ebola and Zika virus disease outbreaks—and potential biological weapons attacks require scalable, flexible diagnosis and treatment. New technologies could enable the rapid identification and development of vaccine candidates, and plant-based antibody production systems.

Shifting ownership models in biotechnology

The rise of off-patent, generic tools and the lowering of technical barriers for engineering biology has the potential to help those in low-resource settings, benefit from developing a sustainable bioeconomy based on local needs and priorities, particularly where new advances are made open for others to build on.

Dr Jenny Molloy comments: “One theme that emerged repeatedly was that of inequality of access to the technology and its benefits. The rise of open source, off-patent tools could enable widespread sharing of knowledge within the biological engineering field and increase access to benefits for those in developing countries.”

Professor Johnathan Napier from Rothamsted Research adds: “The challenges embodied in the Sustainable Development Goals will require all manner of ideas and innovations to deliver significant outcomes. In agriculture, we are on the cusp of new paradigms for how and what we grow, and where. Demonstrating the fairness and usefulness of such approaches is crucial to ensure public acceptance and also to delivering impact in a meaningful way.”

Dr Christian R. Boehm concludes: “As these technologies emerge and develop, we must ensure public trust and acceptance. People may be willing to accept some of the benefits, such as the shift in ownership away from big business and towards more open science, and the ability to address problems that disproportionately affect the developing world, such as food security and disease. But proceeding without the appropriate safety precautions and societal consensus—whatever the public health benefits—could damage the field for many years to come.”

The research was made possible by the Centre for the Study of Existential Risk, the Synthetic Biology Strategic Research Initiative (both at the University of Cambridge), and the Future of Humanity Institute (University of Oxford). It was based on a workshop co-funded by the Templeton World Charity Foundation and the European Research Council under the European Union’s Horizon 2020 research and innovation programme.

Here’s a link to and a citation for the paper,

A transatlantic perspective on 20 emerging issues in biological engineering by Bonnie C Wintle, Christian R Boehm, Catherine Rhodes, Jennifer C Molloy, Piers Millett, Laura Adam, Rainer Breitling, Rob Carlson, Rocco Casagrande, Malcolm Dando, Robert Doubleday, Eric Drexler, Brett Edwards, Tom Ellis, Nicholas G Evans, Richard Hammond, Jim Haseloff, Linda Kahl, Todd Kuiken, Benjamin R Lichman, Colette A Matthewman, Johnathan A Napier, Seán S ÓhÉigeartaigh, Nicola J Patron, Edward Perello, Philip Shapira, Joyce Tait, Eriko Takano, William J Sutherland. eLife; 14 Nov 2017; DOI: 10.7554/eLife.30247

This paper is open access and the editors have included their notes to the authors and the authors’ response.

You may have noticed that I highlighted a portion of the text concerning synthetic gene drives. Coincidentally I ran across a November 16, 2017 article by Ed Yong for The Atlantic where the topic is discussed within the context of a project in New Zealand, ‘Predator Free 2050’ (Note: A link has been removed),

Until the 13th century, the only land mammals in New Zealand were bats. In this furless world, local birds evolved a docile temperament. Many of them, like the iconic kiwi and the giant kakapo parrot, lost their powers of flight. Gentle and grounded, they were easy prey for the rats, dogs, cats, stoats, weasels, and possums that were later introduced by humans. Between them, these predators devour more than 26 million chicks and eggs every year. They have already driven a quarter of the nation’s unique birds to extinction.

Many species now persist only in offshore islands where rats and their ilk have been successfully eradicated, or in small mainland sites like Zealandia where they are encircled by predator-proof fences. The songs in those sanctuaries are echoes of the New Zealand that was.

But perhaps, they also represent the New Zealand that could be.

In recent years, many of the country’s conservationists and residents have rallied behind Predator-Free 2050, an extraordinarily ambitious plan to save the country’s birds by eradicating its invasive predators. Native birds of prey will be unharmed, but Predator-Free 2050’s research strategy, which is released today, spells doom for rats, possums, and stoats (a large weasel). They are to die, every last one of them. No country, anywhere in the world, has managed such a task in an area that big. The largest island ever cleared of rats, Australia’s Macquarie Island, is just 50 square miles in size. New Zealand is 2,000 times bigger. But, the country has committed to fulfilling its ecological moonshot within three decades.

In 2014, Kevin Esvelt, a biologist at MIT, drew a Venn diagram that troubles him to this day. In it, he and his colleagues laid out several possible uses for gene drives—a nascent technology for spreading designer genes through groups of wild animals. Typically, a given gene has a 50-50 chance of being passed to the next generation. But gene drives turn that coin toss into a guarantee, allowing traits to zoom through populations in just a few generations. There are a few natural examples, but with CRISPR, scientists can deliberately engineer such drives.

Suppose you have a population of rats, roughly half of which are brown, and the other half white. Now, imagine there is a gene that affects each rat’s color. It comes in two forms, one leading to brown fur, and the other leading to white fur. A male with two brown copies mates with a female with two white copies, and all their offspring inherit one of each. Those offspring breed themselves, and the brown and white genes continue cascading through the generations in a 50-50 split. This is the usual story of inheritance. But you can subvert it with CRISPR, by programming the brown gene to cut its counterpart and replace it with another copy of itself. Now, the rats’ children are all brown-furred, as are their grandchildren, and soon the whole population is brown.

Forget fur. The same technique could spread an antimalarial gene through a mosquito population, or drought-resistance through crop plants. The applications are vast, but so are the risks. In theory, gene drives spread so quickly and relentlessly that they could rewrite an entire wild population, and once released, they would be hard to contain. If the concept of modifying the genes of organisms is already distasteful to some, gene drives magnify that distaste across national, continental, and perhaps even global scales.

These excerpts don’t do justice to this thought-provoking article. If you have time, I recommend reading it in its entirety  as it provides some insight into gene drives and, with some imagination on the reader’s part, the potential for the other technologies discussed in the report.

One last comment, I notice that Eric Drexler is cited as on the report’s authors. He’s familiar to me as K. Eric Drexler, the author of the book that popularized nanotechnology in the US and other countries, Engines of Creation (1986) .

A cheaper way to make artificial organs

In the quest to develop artificial organs, the University of British Columbia (UBC) is the not the first research institution that comes to my mind. It seems I may need to reevaluate now that UBC (Okanagan) has announced some work on bio-inks and artificial organs in a Sept. 12, 2017 news  release (also on EurekAlert) by Patty Wellborn,,

A new bio-ink that may support a more efficient and inexpensive fabrication of human tissues and organs has been created by researchers at UBC’s Okanagan campus.

Keekyoung Kim, an assistant professor at UBC Okanagan’s School of Engineering, says this development can accelerate advances in regenerative medicine.

Using techniques like 3D printing, scientists are creating bio-material products that function alongside living cells. These products are made using a number of biomaterials including gelatin methacrylate (GelMA), a hydrogel that can serve as a building block in bio-printing. This type of bio-material—called bio-ink—are made of living cells, but can be printed and molded into specific organ or tissue shapes.

The UBC team analyzed the physical and biological properties of three different GelMA hydrogels—porcine skin, cold-water fish skin and cold-soluble gelatin. They found that hydrogel made from cold-soluble gelatin (gelatin which dissolves without heat) was by far the best performer and a strong candidate for future 3D organ printing.

“A big drawback of conventional hydrogel is its thermal instability. Even small changes in temperature cause significant changes in its viscosity or thickness,” says Kim. “This makes it problematic for many room temperature bio-fabrication systems, which are compatible with only a narrow range of hydrogel viscosities and which must generate products that are as uniform as possible if they are to function properly.”

Kim’s team created two new hydrogels—one from fish skin, and one from cold-soluble gelatin—and compared their properties to those of porcine skin GelMA. Although fish skin GelMA had some benefits, cold-soluble GelMA was the top overall performer. Not only could it form healthy tissue scaffolds, allowing cells to successfully grow and adhere to it, but it was also thermally stable at room temperature.

The UBC team also demonstrated that cold-soluble GelMA produces consistently uniform droplets at temperatures, thus making it an excellent choice for use in 3D bio-printing.

“We hope this new bio-ink will help researchers create improved artificial organs and lead to the development of better drugs, tissue engineering and regenerative therapies,” Kim says. “The next step is to investigate whether or not cold-soluble GelMA-based tissue scaffolds are can be used long-term both in the laboratory and in real-world transplants.”

Three times cheaper than porcine skin gelatin, cold-soluble gelatin is used primarily in culinary applications.

Here’s a link to and a citation for the paper,

Comparative study of gelatin methacrylate hydrogels from different sources for biofabrication applications by Zongjie Wang, Zhenlin Tian, Fredric Menard, and Keekyoung Kim. Biofabrication, Volume 9, Number 4 Special issue on Bioinks https://doi.org/10.1088/1758-5090/aa83cf Published 21 August 2017

© 2017 IOP Publishing Ltd

This paper is behind a paywall.

‘Origami organs’ for tissue engineering

This is a different approach to tissue engineering and its the consequence of a serendipitous accident.  From an Aug. 7, 2017 Northwestern University news release (also on EurekAlert),

Northwestern Medicine scientists and engineers have invented a range of bioactive “tissue papers” made of materials derived from organs that are thin and flexible enough to even fold into an origami bird. The new biomaterials can potentially be used to support natural hormone production in young cancer patients and aid wound healing.

The tissue papers are made from structural proteins excreted by cells that give organs their form and structure. The proteins are combined with a polymer to make the material pliable.

In the study, individual types of tissue papers were made from ovarian, uterine, kidney, liver, muscle or heart proteins obtained by processing pig and cow organs. Each tissue paper had specific cellular properties of the organ from which it was made.

The article describing the tissue paper and its function will be published Aug. 7 in the journal Advanced Functional Materials.

“This new class of biomaterials has potential for tissue engineering and regenerative medicine as well as drug discovery and therapeutics,” corresponding author Ramille Shah said. “It’s versatile and surgically friendly.”

Shah is an assistant professor of surgery at the Feinberg School of Medicine and an assistant professor of materials science and engineering at McCormick School of Engineering. She also is a member of the Simpson Querrey Institute for BioNanotechnology.

For wound healing, Shah thinks the tissue paper could provide support and the cell signaling needed to help regenerate tissue to prevent scarring and accelerate healing.

The tissue papers are made from natural organs or tissues. The cells are removed, leaving the natural structural proteins – known as the extracellular matrix – that then are dried into a powder and processed into the tissue papers. Each type of paper contains residual biochemicals and protein architecture from its original organ that can stimulate cells to behave in a certain way.

In the lab of reproductive scientist Teresa Woodruff, the tissue paper made from a bovine ovary was used to grow ovarian follicles when they were cultured in vitro. The follicles (eggs and hormone-producing cells) grown on the tissue paper produced hormones necessary for proper function and maturation.

“This could provide another option to restore normal hormone function to young cancer patients who often lose their hormone function as a result of chemotherapy and radiation,” Woodruff, a study coauthor, said.

A strip of the ovarian paper with the follicles could be implanted under the arm to restore hormone production for cancer patients or even women in menopause.

Woodruff is the director of the Oncofertility Consortium and the Thomas J. Watkins Memorial Professor of Obstetrics and Gynecology at Feinberg.

In addition, the tissue paper made from various organs separately supported the growth of adult human stem cells. Scientists placed human bone marrow stem cells on the tissue paper, and all the stem cells attached and multiplied over four weeks.

“That’s a good sign that the paper supports human stem cell growth,” said first author Adam Jakus, who developed the tissue papers. “It’s an indicator that once we start using tissue paper in animal models it will be biocompatible.”

The tissue papers feel and behave much like standard office paper when they are dry, Jakus said. Jakus simply stacks them in a refrigerator or a freezer. He even playfully folded them into an origami bird.

“Even when wet, the tissue papers maintain their mechanical properties and can be rolled, folded, cut and sutured to tissue,” he said.

Jakus was a Hartwell postdoctoral fellow in Shah’s lab for the study and is now chief technology officer and cofounder of the startup company Dimension Inx, LLC, which was also cofounded by Shah. The company will develop, produce and sell 3-D printable materials primarily for medical applications. The Intellectual Property is owned by Northwestern University and will be licensed to Dimension Inx.

An Accidental Spill Sparked Invention

An accidental spill of 3-D printing ink in Shah’s lab by Jakus sparked the invention of the tissue paper. Jakus was attempting to make a 3-D printable ovary ink similar to the other 3-D printable materials he previously developed to repair and regenerate bone, muscle and nerve tissue. When he went to wipe up the spill, the ovary ink had already formed a dry sheet.

“When I tried to pick it up, it felt strong,” Jakus said. “I knew right then I could make large amounts of bioactive materials from other organs. The light bulb went on in my head. I could do this with other organs.”

“It is really amazing that meat and animal by-products like a kidney, liver, heart and uterus can be transformed into paper-like biomaterials that can potentially regenerate and restore function to tissues and organs,” Jakus said. “I’ll never look at a steak or pork tenderloin the same way again.”

For those who like their news in a video,

As someone who once made baklava, that does not look like filo pastry, where an individual sheet is quite thin and rips easily. Enough said.

Here’s a link to and a citation for the paper,

“Tissue Papers” from Organ-Specific Decellularized Extracellular Matrices by Adam E. Jakus, Monica M. Laronda, Alexandra S. Rashedi, Christina M. Robinson, Chris Lee, Sumanas W. Jordan, Kyle E. Orwig, Teresa K. Woodruff, and Ramille N. Shah. Advnaced Functional Materials DOI: 10.1002/adfm.201700992 Version of Record online: 7 AUG 2017

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Mussels to muscles for biocompatible fibres

Mussels and barnacles in the intertidal near Newquay, Cornwall, England.
Wilson44691 at English Wikipedia – Photograph taken by Mark A. Wilson (Department of Geology, The College of Wooster

I love puns and word play so I was happy to see this in a June 9, 2017 news item on ScienceDaily,

Rice University chemists can thank the mussel for putting the muscle into their new macroscale scaffold fibers.

A June 9, 2017 Rice University news release (also on EurekAlert), which originated the news item, provides more details about the research,

The Rice lab of chemist Jeffrey Hartgerink had already figured out how to make biocompatible nanofibers out of synthetic peptides. In new work, the lab is using an amino acid found in the sticky feet of mussels to make those fibers line up into strong hydrogel strings.

Hartgerink and Rice graduate student I-Che Li introduced their room-temperature method this month in an open-access paper in the Journal of the American Chemical Society.

The hydrogel strings can be picked up and moved with tweezers, and Li said he expects they will help labs gain better control over the growth of cell cultures.

“Usually when cells grow on a surface, they spread randomly,” he said. “There are a lot of biomaterials we want to grow in a specific direction. With the hydrogel scaffold aligned, we can expect cells to grow the way we want them to. One example would be neuron cells, which we want to grow head-to-tail to aid nerve regeneration.

“Basically, this could allow us to direct cell growth from here to there,” he said. “That’s why this material is so exciting.”

In previous research Hartgerink’s lab had developed synthetic hydrogels that could be injected into the body to serve as scaffolds for tissue growth. The hydrogels contained hydrophobic peptides that self-assembled into fibers about 6 nanometers wide and up to several microns long. However, because the fibers did not interact with one other, they generally appeared in microscope images as a tangled mass.

Experiments showed the fibers could be coaxed into alignment with the application of shear forces, in the same way that playing cards are aligned during shuffling by pushing on both the top and bottom of the deck.

Hartgerink and Li decided to try pushing the fibers through a needle to force them into alignment, a process that would be easier if the material was water soluble. So they added a chain of amino acids known as DOPA to the sides of the fibers to allow them to remain water-soluble in the syringe, Li said.

DOPA — short for 3,4-dihydroxyphenylalanine — is the compound that lets mussels stick to just about anything. Hartgerink and Li found that the combination of DOPA and shear stress from passing through the needle prompted the fibers to form visible, rope-like bundles.

They also found that DOPA promoted chemical cross-linking reactions that helped the bundles hold their shape. “DOPA is really sensitive to oxidizing agents,” Li said. “Even exposing DOPA to air oxidizes it, and that aids in cross-linking the fibers.”

As a bonus, the aligned fibers also proved to have a curious and useful optical property called “uniform birefringence,” or double-refraction. Li said this could allow researchers to use polarized light to see exactly where the aligned fibers are, even if they’re covered by cells.

“This will be an important technique for us to make sure of the long-range order of fiber alignment when we are testing directed cell growth,” he said.

The researchers expect the aligned fibers can be used for macroscale medical applications but with nanoscale control over the structures.

“Self-assembly is basically the ability of a molecule to make ordered structure from chaos, and what I-Che has done is push this organization to a new level with his aligned strings,” said Hartgerink, a professor of chemistry and of bioengineering. “With this material, we are excited to see if we can impose this organization onto the growth of cells that interact with it.”

Here’s a link to and a citation for the paper,

Covalent Capture of Aligned Self-Assembling Nanofibers by I-Che Li and Jeffrey D. Hartgerink. J. Am. Chem. Soc., Article ASAP DOI: 10.1021/jacs.7b04655 Publication Date (Web): June 5, 2017

Copyright © 2017 American Chemical Society

This paper is open access.

A nano fabrication technique used to create next generation heart valve

I am going to have take the researchers’ word that these somehow lead to healthy heart valve tissue,

In rotary jet spinning technology, a rotating nozzle extrudes a solution of extracellular matrix (ECM) into nanofibers that wrap themselves around heart valve-shaped mandrels. By using a series of mandrels with different sizes, the manufacturing process becomes fully scalable and is able to provide JetValves for all age groups and heart sizes. Credit: Wyss Institute at Harvard University

From a May 18, 2017 news item on ScienceDaily,

The human heart beats approximately 35 million times every year, effectively pumping blood into the circulation via four different heart valves. Unfortunately, in over four million people each year, these delicate tissues malfunction due to birth defects, age-related deteriorations, and infections, causing cardiac valve disease.

Today, clinicians use either artificial prostheses or fixed animal and cadaver-sourced tissues to replace defective valves. While these prostheses can restore the function of the heart for a while, they are associated with adverse comorbidity and wear down and need to be replaced during invasive and expensive surgeries. Moreover, in children, implanted heart valve prostheses need to be replaced even more often as they cannot grow with the child.

A team lead by Kevin Kit Parker, Ph.D. at Harvard University’s Wyss Institute for Biologically Inspired Engineering recently developed a nanofiber fabrication technique to rapidly manufacture heart valves with regenerative and growth potential. In a paper published in Biomaterials, Andrew Capulli, Ph.D. and colleagues fabricated a valve-shaped nanofiber network that mimics the mechanical and chemical properties of the native valve extracellular matrix (ECM). To achieve this, the team used the Parker lab’s proprietary rotary jet spinning technology — in which a rotating nozzle extrudes an ECM solution into nanofibers that wrap themselves around heart valve-shaped mandrels. “Our setup is like a very fast cotton candy machine that can spin a range of synthetic and natural occurring materials. In this study, we used a combination of synthetic polymers and ECM proteins to fabricate biocompatible JetValves that are hemodynamically competent upon implantation and support cell migration and re-population in vitro. Importantly, we can make human-sized JetValves in minutes — much faster than possible for other regenerative prostheses,” said Parker.

A May 18,2017 Wyss Institute for Biologically Inspired Engineering news release (also on EurekAlert), which originated the news item, expands on the theme of Jetvalves,

To further develop and test the clinical potential of JetValves, Parker’s team collaborated with the translational team of Simon P. Hoerstrup, M.D., Ph.D., at the University of Zurich in Switzerland, which is a partner institution with the Wyss Institute. As a leader in regenerative heart prostheses, Hoerstrup and his team in Zurich have previously developed regenerative, tissue-engineered heart valves to replace mechanical and fixed-tissue heart valves. In Hoerstrup’s approach, human cells directly deposit a regenerative layer of complex ECM on biodegradable scaffolds shaped as heart valves and vessels. The living cells are then eliminated from the scaffolds resulting in an “off-the-shelf” human matrix-based prostheses ready for implantation.

In the paper, the cross-disciplinary team successfully implanted JetValves in sheep using a minimally invasive technique and demonstrated that the valves functioned properly in the circulation and regenerated new tissue. “In our previous studies, the cell-derived ECM-coated scaffolds could recruit cells from the receiving animal’s heart and support cell proliferation, matrix remodeling, tissue regeneration, and even animal growth. While these valves are safe and effective, their manufacturing remains complex and expensive as human cells must be cultured for a long time under heavily regulated conditions. The JetValve’s much faster manufacturing process can be a game-changer in this respect. If we can replicate these results in humans, this technology could have invaluable benefits in minimizing the number of pediatric re-operations,” said Hoerstrup.

In support of these translational efforts, the Wyss Institute for Biologically Inspired Engineering and the University of Zurich announced today a cross-institutional team effort to generate a functional heart valve replacement with the capacity for repair, regeneration, and growth. The team is also working towards a GMP-grade version of their customizable, scalable, and cost-effective manufacturing process that would enable deployment to a large patient population. In addition, the new heart valve would be compatible with minimally invasive procedures to serve both pediatric and adult patients.

The project will be led jointly by Parker and Hoerstrup. Parker is a Core Faculty member of the Wyss Institute and the Tarr Family Professor of Bioengineering and Applied Physics at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS). Hoerstrup is Chair and Director of the University of Zurich’s Institute for Regenerative Medicine (IREM), Co-Director of the recently founded Wyss Translational Center Zurich and a Wyss Institute Associate Faculty member.

Since JetValves can be manufactured in all desired shapes and sizes, and take seconds to minutes to produce, the team’s goal is to provide customized, ready-to-use, regenerative heart valves much faster and at much lower cost than currently possible.

“Achieving the goal of minimally invasive, low-cost regenerating heart valves could have tremendous impact on patients’ lives across age-, social- and geographical boundaries. Once again, our collaborative team structure that combines unique and leading expertise in bioengineering, regenerative medicine, surgical innovation and business development across the Wyss Institute and our partner institutions, makes it possible for us to advance technology development in ways not possible in a conventional academic laboratory,” said Wyss Institute Founding Director Donald Ingber, M.D., Ph.D., who is also the Judah Folkman Professor of Vascular Biology at HMS and the Vascular Biology Program at Boston Children’s Hospital, as well as Professor of Bioengineering at SEAS.

This scanning electron microscopy image shows how extracellular matrix (ECM) nanofibers generated with JetValve technology are arranged in parallel networks with physical properties comparable to those found in native heart tissue. Credit: Wyss Institute at Harvard University

Here’s a link to and a citation for the paper,

JetValve: Rapid manufacturing of biohybrid scaffolds for biomimetic heart valve replacement by Andrew K. Capulli, Maximillian Y. Emmert, Francesco S. Pasqualini, b, Debora Kehl, Etem Caliskan, Johan U. Lind, Sean P. Sheehy, Sung Jin Park, Seungkuk Ahn, Benedikt Webe, Josue A. Goss. Biomaterials Volume 133, July 2017, Pages 229–241  https://doi.org/10.1016/j.biomaterials.2017.04.033

This paper is behind a paywall.

3D bioprinting: a conference about the latest trends (May 3 – 5, 2017 at the University of British Columbia, Vancouver)

The University of British Columbia’s (UBC) Peter Wall Institute for Advanced Studies (PWIAS) is hosting along with local biotech firm, Aspect Biosystems, a May 3 -5, 2017 international research roundtable known as ‘Printing the Future of Therapeutics in 3D‘.

A May 1, 2017 UBC news release (received via email) offers some insight into the field of bioprinting from one of the roundtable organizers,

This week, global experts will gather [4] at the University of British
Columbia to discuss the latest trends in 3D bioprinting—a technology
used to create living tissues and organs.

In this Q&A, UBC chemical and biological engineering professor
Vikramaditya Yadav [5], who is also with the Regenerative Medicine
Cluster Initiative in B.C., explains how bioprinting could potentially
transform healthcare and drug development, and highlights Canadian
innovations in this field.

WHY IS 3D BIOPRINTING SIGNIFICANT?

Bioprinted tissues or organs could allow scientists to predict
beforehand how a drug will interact within the body. For every
life-saving therapeutic drug that makes its way into our medicine
cabinets, Health Canada blocks the entry of nine drugs because they are
proven unsafe or ineffective. Eliminating poor-quality drug candidates
to reduce development costs—and therefore the cost to consumers—has
never been more urgent.

In Canada alone, nearly 4,500 individuals are waiting to be matched with
organ donors. If and when bioprinters evolve to the point where they can
manufacture implantable organs, the concept of an organ transplant
waiting list would cease to exist. And bioprinted tissues and organs
from a patient’s own healthy cells could potentially reduce the risk
of transplant rejection and related challenges.

HOW IS THIS TECHNOLOGY CURRENTLY BEING USED?

Skin, cartilage and bone, and blood vessels are some of the tissue types
that have been successfully constructed using bioprinting. Two of the
most active players are the Wake Forest Institute for Regenerative
Medicine in North Carolina, which reports that its bioprinters can make
enough replacement skin to cover a burn with 10 times less healthy
tissue than is usually needed, and California-based Organovo, which
makes its kidney and liver tissue commercially available to
pharmaceutical companies for drug testing.

Beyond medicine, bioprinting has already been commercialized to print
meat and artificial leather. It’s been estimated that the global
bioprinting market will hit $2 billion by 2021.

HOW IS CANADA INVOLVED IN THIS FIELD?

Canada is home to some of the most innovative research clusters and
start-up companies in the field. The UBC spin-off Aspect Biosystems [6]
has pioneered a bioprinting paradigm that rapidly prints on-demand
tissues. It has successfully generated tissues found in human lungs.

Many initiatives at Canadian universities are laying strong foundations
for the translation of bioprinting and tissue engineering into
mainstream medical technologies. These include the Regenerative Medicine
Cluster Initiative in B.C., which is headed by UBC, and the University
of Toronto’s Institute of Biomaterials and Biomedical Engineering.

WHAT ETHICAL ISSUES DOES BIOPRINTING CREATE?

There are concerns about the quality of the printed tissues. It’s
important to note that the U.S. Food and Drug Administration and Health
Canada are dedicating entire divisions to regulation of biomanufactured
products and biomedical devices, and the FDA also has a special division
that focuses on regulation of additive manufacturing – another name
for 3D printing.

These regulatory bodies have an impressive track record that should
assuage concerns about the marketing of substandard tissue. But cost and
pricing are arguably much more complex issues.

Some ethicists have also raised questions about whether society is not
too far away from creating Replicants, à la _Blade Runner_. The idea is
fascinating, scary and ethically grey. In theory, if one could replace
the extracellular matrix of bones and muscles with a stronger substitute
and use cells that are viable for longer, it is not too far-fetched to
create bones or muscles that are stronger and more durable than their
natural counterparts.

WILL DOCTORS BE PRINTING REPLACEMENT BODY PARTS IN 20 YEARS’ TIME?

This is still some way off. Optimistically, patients could see the
technology in certain clinical environments within the next decade.
However, some technical challenges must be addressed in order for this
to occur, beginning with faithful replication of the correct 3D
architecture and vascularity of tissues and organs. The bioprinters
themselves need to be improved in order to increase cell viability after
printing.

These developments are happening as we speak. Regulation, though, will
be the biggest challenge for the field in the coming years.

There are some events open to the public (from the international research roundtable homepage),

OPEN EVENTS

You’re invited to attend the open events associated with Printing the Future of Therapeutics in 3D.

Café Scientifique

Thursday, May 4, 2017
Telus World of Science
5:30 – 8:00pm [all tickets have been claimed as of May 2, 2017 at 3:15 pm PT]

3D Bioprinting: Shaping the Future of Health

Imagine a world where drugs are developed without the use of animals, where doctors know how a patient will react to a drug before prescribing it and where patients can have a replacement organ 3D-printed using their own cells, without dealing with long donor waiting lists or organ rejection. 3D bioprinting could enable this world. Join us for lively discussion and dessert as experts in the field discuss the exciting potential of 3D bioprinting and the ethical issues raised when you can print human tissues on demand. This is also a rare opportunity to see a bioprinter live in action!

Open Session

Friday, May 5, 2017
Peter Wall Institute for Advanced Studies
2:00 – 7:00pm

A Scientific Discussion on the Promise of 3D Bioprinting

The medical industry is struggling to keep our ageing population healthy. Developing effective and safe drugs is too expensive and time-consuming to continue unchanged. We cannot meet the current demand for transplant organs, and people are dying on the donor waiting list every day.  We invite you to join an open session where four of the most influential academic and industry professionals in the field discuss how 3D bioprinting is being used to shape the future of health and what ethical challenges may be involved if you are able to print your own organs.

ROUNDTABLE INFORMATION

The University of British Columbia and the award-winning bioprinting company Aspect Biosystems, are proud to be co-organizing the first “Printing the Future of Therapeutics in 3D” International Research Roundtable. This event will congregate global leaders in tissue engineering research and pharmaceutical industry experts to discuss the rapidly emerging and potentially game-changing technology of 3D-printing living human tissues (bioprinting). The goals are to:

Highlight the state-of-the-art in 3D bioprinting research
Ideate on disruptive innovations that will transform bioprinting from a novel research tool to a broadly adopted systematic practice
Formulate an actionable strategy for industry engagement, clinical translation and societal impact
Present in a public forum, key messages to educate and stimulate discussion on the promises of bioprinting technology

The Roundtable will bring together a unique collection of industry experts and academic leaders to define a guiding vision to efficiently deploy bioprinting technology for the discovery and development of new therapeutics. As the novel technology of 3D bioprinting is more broadly adopted, we envision this Roundtable will become a key annual meeting to help guide the development of the technology both in Canada and globally.

We thank you for your involvement in this ground-breaking event and look forward to you all joining us in Vancouver for this unique research roundtable.

Kind Regards,
The Organizing Committee
Christian Naus, Professor, Cellular & Physiological Sciences, UBC
Vikram Yadav, Assistant Professor, Chemical & Biological Engineering, UBC
Tamer Mohamed, CEO, Aspect Biosystems
Sam Wadsworth, CSO, Aspect Biosystems
Natalie Korenic, Business Coordinator, Aspect Biosystems

I’m glad to see this event is taking place—and with public events too! (Wish I’d seen the Café Scientifique announcement earlier when I first checked for tickets  yesterday. I was hoping there’d been some cancellations today.) Finally, for the interested, you can find Aspect Biosystems here.

Recycling apples to regenerate bone and cartilage tissue

A March 30, 2017 news item on phys.org announces research utilizing apple waste as a matrix for regenerating bones and cartilage,

Researchers from UPM and CSIC [both organizations are in Spain] have employed waste from the agri-food industry to develop biomaterials that act as matrices to regenerate bone and cartilage tissues, which is of great interest for the treatment of diseases related to aging.

The researchers have produced biocompatible materials from apple pomace resulting from juice production. These materials can be used as 3-D matrices for the regeneration of bone and cartilage tissues, useful in regenerative medicine for diseases such as osteoporosis, arthritis or osteoarthritis, all of them rising due to the increasing average age of the population.

A March 30, 2017 Universidad Politécnica de Madrid (UPM) press release, which originated the news item,, expands on the theme,

Apple pomace is an abundant raw material. The world production of apples was more than 70 million tons in 2015, of which the European Union contributed with more than 15%, while half a million tons of which came from Spain. About 75% of apples can be converted into juice and the rest, known as apple pomace, that contains approximately 20–30% dried matter, is used mainly as animal feed or for compost. Since apple pomace is generated in vast quantities and contains a large fraction of water, it poses storage problems and requires immediate treatments to prevent putrefaction. An alternative of great environmental interest is its transformation into value added commodities, thus reducing the volume of waste.

The procedure of the multivalorization of apple pomace carried out by the UPM and CSIC researchers are based on sequential extractions of different bioactive molecules, such as antioxidants or pectin, to finally obtain the waste from which they prepare a biomaterial with suitable porosity and texture to be used in tissue engineering.

The primary extraction of antioxidants and carbohydrates constitutes 2% of the dry weight of apple pomace and pectin extraction is 10%. The extracted chemical cells have a recognized value as nutraceuticals and pectin is a material of great utility in different medical applications, given its high biocompatibility and being part of antitumor drugs or in the treatment of coetaneous wounds.

Furthermore, it has been found that the materials remaining after antioxidant and pectin removal from apple pomace can still be designed with adequate structure, texture and composition to grow diverse types of cells. In this particularly case, the chosen cells were osteoblasts and chondrocytes, both of them related to the regeneration of bone and cartilage tissues because of their application in regenerative medicine in diseases such as osteoporosis, arthritis or osteoarthritis.

Today, there are products in the market with the same applications, however they have a high price reaching over €100 per gram, while waste used in this work hardly reaches €100 per ton. For this reason, there are consistent incentives to convert this waste into final products of great added value.

According to Milagro Ramos, a female researcher of the study, “with this approach we achieve a double goal, firstly using waste as a renewable raw material of high value and chemical diversity, and secondly, to reduce the impact of such waste accumulation on the environment”.

Thanks to the new materials obtained in this work, researchers are developing new technological applications that allow them to structure customized biomaterials through 3D printing techniques.

Here’s a link to and a citation for the paper,

Multivalorization of apple pomace towards materials and chemicals. Waste to wealth by Malcolm Yates, Milagros Ramos Gomez, Maria A. Martin-Luengo, Violeta Zurdo Ibañez, Ana Maria Martinez Serrano. Journal of Cleaner Production Volume 143, 1 February 2017, Pages 847–853  http://doi.org/10.1016/j.jclepro.2016.12.036

This paper is behind a paywall.