While most 3D printers deposit melted plastic in carefully controlled positions to build up a physical model, a similar process called “bioprinting” can be accomplished with biological materials. Commercial bioprinters can cost tens of thousands of dollars or more, but as shown here you can make your own using the shell an inexpensive desktop machine.
In this example, a Monoprice MP Select Mini V2 is stripped down to its bones and motors, subbing in an Arduino Mega and RAMPS 1.4 stepper driver board.
A syringe-like extruder is added to push out custom bioink, and the Z-axis switch mounting and Marlin firmware is modified to accommodate the new device. The homing sequence is modeled in the video below, giving a short snippet of how it works.
A team of researchers from the University Medical Centre Utrecht in the Netherlands have created a biofabrication method to create living tissues that replicate cartilage and could potentially be implanted to repair damaged joints.
Experienced by millions and millions across the world, arthritis is a physical disability that nearly one in ten people will have to battle during their lifetime. Arthritis acts by breaking down the cartilage tissue found in joints, which leads to stiffness and swelling, resulting in pain and discomfort for those who develop the condition.
However, at the University Medical Centre Utrecht in the Netherlands, Professor Jos Malda and has research team have created a 3D printable bioink that could allow damaged joints to heal themselves. The bioprinted tissues can be implanted into a living joint, where it would eventually mature into a new tissue and behave like healthy cartilage. This research is being conducted as a part of a project called 3D-JOINT.
Although biomaterials like stem cells have been adapted for 3D printing, there have been difficulties in ensuring that the proper conditions for cellular building are met. While hydrogels are a viable material for delivering living tissue, they are also unable to withstand the mechanical load that some tissues face once implanted into the body.
Strengthening Hydrogel to Transform it into Replacement Cartilage
And so, the Dutch research team is experimenting with different additive materials that will strengthen the hydrogel to the point where it acts as replacement cartilage. The researchers are using a 3D printing process called melt electrowriting, which combines melted polycaprolactone with an electrical field to create fibers that are as thin as a strand of hair.
These microfibers are being used to create scaffolding that can be combined with the hydrogel. “The combination of the hydrogel with the fibres acts in synergy, increasing the strength of the composite over 50 times while still allowing the cells to generate extracellular matrix and mature into a cartilage-like tissue,” Malda said.
The researchers are currently working to expand their methodology to develop larger constructs, and will also experiment with different materials to combine bone and cartilage tissue replacements. The end-goal of their work is to eventually 3D print a complete and functional joint.
As the University Medical Centre Utrecht research has carried on for a couple of years, it’s yet another instance of how bioprinting is advancing to the point where it will soon be safe and compatible for human implants.
A team of engineers from the University of Illinois have developed a free-form isomalt 3D printing technology that produces intricate sugar-based scaffolding, which could potentially be used to grow tissue or study tumors.
Slowly but surely, bioprinting is reshaping the medical landscape in multiple ways, from producing custom scaffolding to quite literally growing organs from stem cells. And now, after this latest development, 3D printing has just become a viable tool to produce intricate scaffolding structures out of sugar. That’s right, sugar…
An engineering team at the University of Illinois has developed a 3D printer that can produce thinly layered networks of isomalt – the sugar alcohol used to make throat lozenges.
The research entails materials and mechanics of free-form isomalt printing, which is a technique where the nozzle travels through space while the dissolved material solidifies. While other types of sugar are prone to burning or crystalizing when 3D printed, the sugar alcohol isomalt works much more efficient for this process.
Matthew Gelber, the first author on the corresponding research paper, believes that the 3D printer could be used design structures such as cells and tissues eventually. However, growing tissues is just one application of the new technology, and there are other commercial applications in the team’s sights.
Professor Rohit Bhargava (left) and PhD Matthew Gelber (right) who developed the free-form 3D printer. (Image: L. Brian Stauffer)
3D Printing Sugar Creates Cylinder Tubes and Tunnels
Called free-form isomalt printing, the technique uses a nozzle that travels freely through space solidifying dissolved materials. Gelber explains:
“Other types of sugar printing have been previously explored, but have problems with the sugar burning or crystallizing. the sugar alcohol isomalt could work for printing applications and is less prone to burning or crystallization. After the materials and the mechanics, the third component was computer science. You have a design of a thing you want to make; how do you tell the printer to make it? How do you figure out the sequence to print all these intersecting filaments so it doesn’t collapse?”
Professor Rohit Bhargava at the Cancer Center at Illinois describes that the primary advantage of free-form structures is their ability to produce thin tubes that include circular cross-sections. This has previously not been achievable with polymers. The dissolved sugar on the other hand creates cylinder tubes and tunnels that resemble blood vessels.
In order to create optimized design scaffolds and map out printing pathways, the researchers collaborated with Greg Hurst at Wolfram Research on an algorithm. These free-form structures are able to be made into thin tubes with circular cross-sections without the need for support structures. Once the sugar is dissolved, there’s a series of connected cylindrical tubes that resemble blood vessels, making it possible to transport nutrients in tissue or to create channels in microfluidic devices
On top of that, the system also allows for more accurate control over the mechanical properties of each part. Bhargava explains:
“For example, we printed a bunny. We could, in principle, change the mechanical properties of the tail of the bunny to be different from the back of the bunny, and yet be different from the ears. This is very important biologically. In layer-by-layer printing, you have the same material and you’re depositing the same amount, so it’s very difficult to adjust the mechanical properties.
Needless to say, this recent development from the University of Illinois could be a game-changer in the medical landscape, presenting various possible applications, such as developing scaffolding to grow tissue of study tumors.
The final paper, entitled “Model-guided design and characterization of a high-precision 3D printing process for carbohydrate glass,” has recently been published in Additive Manufacturing.
3D printed bunny using the technology. (Image: Troy Comi)
By embedding platelets into a 3D printed mixture of cells and gel, a team of researchers at the University of Nebraska-Lincoln hope to improve the healing properties of tissue implants and skin grafts with printable body tissue.
Researchers from the University of Nebraska-Lincoln, MIT, and Massachusetts General Hospital have incorporated platelet-rich plasma into a bio-ink — a 3D printed mixture of cells and gel — that could eventually become the basis of skin grafts and regenerative tissue implants.
“The ultimate goal is to print functional tissue constructs that can be implanted to replace or repair damaged tissues,” said Nebraska’s Ali Tamayol, assistant professor of mechanical and materials engineering.
“One of the challenges is to create structures that, when implanted in selected tissues or organs after an injury, will release growth factors that initiate the processes essential for healing and regeneration.”
Jeremy Ruskin, professor of medicine at Harvard Medical School, collaborated with colleagues at Massachusetts General Hospital to show that the bio-ink features an optimal concentration of platelet-rich plasma and can dispense its growth factors over several days. When testing the performance of its platelet-rich ink against a platelet-less counterpart in the lab, the team saw some promising results.
In less than a day, the platelet-rich ink had prompted enough cell migration to cover about 50 percent of an artificial scratch, whereas the platelet-less edition covered just 5 percent. The ink also encouraged more than twice as many mesenchymal stem cells – which can become muscle, cartilage or bone – to migrate toward it during a 24-hour span.
Printable Body Tissue as Personalized Therapies
But these results would mean little if the ink’s gelatinous algae-derived ingredients proved resistant to 3D printing.
To help it maintain its shape, Tamayol and colleagues initially sprinkled the alginate with calcium chloride to forge bonds among some of the material’s polymer chains. This lends it strength without making it too viscous for a 3D printer.
After printing the ink into a desired 3D design, they immersed the structure in a calcium chloride solution to further strengthen it. The human body also happens to raise calcium levels at injury sites, says Tamayol, meaning that it could help reinforce the alginate after implantation.
Once bio-printing technology has matured, he predicts, the alginate could be mixed with a patient’s own cells and platelets to minimize the risk of an immune response.
“There is a trend toward using personalized therapies in many areas of medicine,” said Negar Faramarzi, the lead author of a new study detailing the bio-ink. “We tried to incorporate the growth factors in a way that keeps us on track for those personalized therapies.”
A sheet of bioprinted hydrogels — inspired by the electric eel — is capable of delivering 110 volts of electricity. It has potential to become a soft power source which draws on a biological system’s chemical energy.
Researchers used a 3D bioprinter to create a device which reached 110 volts from hydrogels. Essentially, they were inspired by electric eels’ ability to produce hundreds of volts.
The researchers worked together to stack hydrogels full of varying strengths of salt water. Working on this project was Anirvan Guha, a graduate student at the University of Fribourg’s Adolphe Merkle Institute.
He explains that in the future, this work will hopefully help develop power sources for implantable devices. This could work by offering a soft power source which can draw on a biological system’s chemical energy.
Guha explains that such devices will be able to “utilize the gradients that already exist within the human body. Then you may be able to create a battery which continuously recharges itself, because these ionic gradients are constantly being re-established within the body.”
Creating the Electric Eel Device with a Bioprinter
To create the device, the researchers used a 3D bioprinter to deposit arrays of gel precursor droplets onto plastic substrates.
Guha explains that the printer “deposits little droplets of gel … with the precision and spatial resolution to print an array of almost 2,500 gels on a sheet the size of a normal piece of printer paper.”
It’s necessary to stack thousands of individual hydrogels to generate the volts, but this is easy work for a 3D bioprinter. After this process is complete, the researchers cured the droplets with a UV light. This converted them into solid gels.
Different salinity gels were printed on one substrate which were either high or low. On a second substrate, “cation-selective and anion-selective” gels were printed.
Finally, the researchers would overlay the gels. As they connect, they form a conductive pathway. Essentially, this pathway is what generates up to 110 volts.
Next, the aim is to increase the current which runs through the hydrogel. Guha explains: “Right now, we’re in the range of tens to hundreds of microamperes , which is too low to power most electronic devices.”
Guha will be presenting his research this week at the Biophysical Society 62nd Annual Meeting in San Francisco. Find out more by reading the paper written by Guha and his co-authors called “An eel-inspired artificial electric organ: 110 volts from water and salt”.
Scientists have developed an easy and affordable way to print biological environments without losing their chemical complexities.
Biomedical engineering and the molecular sciences are among the many industries making use of 3D printing in order to find new ways to target drugs or develop human tissues and organs. Although a variety of 3D hydrogel systems have been developed, there are still limitations when it comes to developing more complex biological structures that include a controlled biochemical anisotropy.
Now, a research team at Queen Mary University of London (QMUL) has created a unique 3D-Electrophoresis-Assisted-Lithography (3DEAL) platform which enables scientists to print 3D molecular patterns using hydrogels. This opens the door to the development of more complex biological environments.
3DEAL is an easy-to-use and inexpensive technique to create more complex molecular patterns such as molecular gradients using hydrogels. This way, 3D hydrogel environments can be developed and retain their spatial control of chemical composition and functional patterns.
It is based on the principles of native polyacrylamide gel electrophoresis (NPAGE) – a widely used molecular technique to analyze proteins.
Fluorescent protein patterns with 3D hydrogels. (Image: QMUL)
3DEAL offers improve robustness and lower costs for 3D molecular printing
The 3DEAL incorporates an electrical field as well as a porous mask that is used to localize molecules in the hydrogel regardless of their charge and size. The researchers then went on to demonstrate the technique by creating complex molecular patterns from native proteins.
Professor Alvaro Mata, the lead researcher of the project at Queen Mary’s School of Engineering and Materials Science, explained the potential uses for their 3D molecular printing process:
“The human body is largely made up of anisotropic, hierarchical, and mostly three-dimensional structures. New ways to fabricate environments that can recreate physical and chemical features of such structures would have important implications in the way more efficient drugs are developed or more functional tissue and organ constructs can be engineered.”
Other techniques such as stereolithography or photo-activated bioorthogonal reactions have been able to pattern proteins with hydrogels. However, such techniques require hydrogels with very specific optical properties and are limited in terms of depth of printing. In comparison, the 3DEAL technique allows for high-aspect ratio patterns. It can also be modified to print and pattern molecules.
Some of the main advantages of the technique include its robustness, ease of use, cost effectiveness, as well as versatility to be used with various hydrogels and molecule types.
The team plans to continue its research to assess more complex patterning and continue focusing on tissue engineering applications.
The research was funded by the ERC Starting Grant Strofunscaff and has been published in the journal Advanced Functional Materials.
Fluorescently-labeled protein patterns within different types of 3D hydrogels 5. (Photo Credit: Queen Mary, University of London)
Um dir ein optimales Erlebnis zu bieten, verwenden wir Technologien wie Cookies, um Geräteinformationen zu speichern und/oder darauf zuzugreifen. Wenn du diesen Technologien zustimmst, können wir Daten wie das Surfverhalten oder eindeutige IDs auf dieser Website verarbeiten. Wenn du deine Einwillligung nicht erteilst oder zurückziehst, können bestimmte Merkmale und Funktionen beeinträchtigt werden.
Funktional
Immer aktiv
Die technische Speicherung oder der Zugang ist unbedingt erforderlich für den rechtmäßigen Zweck, die Nutzung eines bestimmten Dienstes zu ermöglichen, der vom Teilnehmer oder Nutzer ausdrücklich gewünscht wird, oder für den alleinigen Zweck, die Übertragung einer Nachricht über ein elektronisches Kommunikationsnetz durchzuführen.
Vorlieben
Die technische Speicherung oder der Zugriff ist für den rechtmäßigen Zweck der Speicherung von Präferenzen erforderlich, die nicht vom Abonnenten oder Benutzer angefordert wurden.
Statistiken
Die technische Speicherung oder der Zugriff, der ausschließlich zu statistischen Zwecken erfolgt.Die technische Speicherung oder der Zugriff, der ausschließlich zu anonymen statistischen Zwecken verwendet wird. Ohne eine Vorladung, die freiwillige Zustimmung deines Internetdienstanbieters oder zusätzliche Aufzeichnungen von Dritten können die zu diesem Zweck gespeicherten oder abgerufenen Informationen allein in der Regel nicht dazu verwendet werden, dich zu identifizieren.
Marketing
Die technische Speicherung oder der Zugriff ist erforderlich, um Nutzerprofile zu erstellen, um Werbung zu versenden oder um den Nutzer auf einer Website oder über mehrere Websites hinweg zu ähnlichen Marketingzwecken zu verfolgen.
