Sacrificial ink-writing technique allows 3D printing of large, vascularized human organ building blocks
20 people die every day waiting for an organ transplant in the United States, and while more than 30,000 transplants are now performed annually, there are over 113,000 patients currently on organ waitlists. Artificially grown human organs are seen by many as the “holy grail” for resolving this organ shortage, and advances in 3D printing have led to a boom in using that technique to build living tissue constructs in the shape of human organs. However, all 3D-printed human tissues to date lack the cellular density and organ-level functions required for them to be used in organ repair and replacement.
Now, a new technique called SWIFT (sacrificial writing into functional tissue) created by researchers from Harvard’s Wyss Institute for Biologically Inspired Engineering and John A. Paulson School of Engineering and Applied Sciences (SEAS), overcomes that major hurdle by 3D printing vascular channels into living matrices composed of stem-cell-derived organ building blocks (OBBs), yielding viable, organ-specific tissues with high cell density and function. The research is reported in Science Advances.
“This is an entirely new paradigm for tissue fabrication,” said co-first author Mark Skylar-Scott, Ph.D., a Research Associate at the Wyss Institute. “Rather than trying to 3D-print an entire organ’s worth of cells, SWIFT focuses on only printing the vessels necessary to support a living tissue construct that contains large quantities of OBBs, which may ultimately be used therapeutically to repair and replace human organs with lab-grown versions containing patients’ own cells.”
SWIFT involves a two-step process that begins with forming hundreds of thousands of stem-cell-derived aggregates into a dense, living matrix of OBBs that contains about 200 million cells per milliliter. Next, a vascular network through which oxygen and other nutrients can be delivered to the cells is embedded within the matrix by writing and removing a sacrificial ink. “Forming a dense matrix from these OBBs kills two birds with one stone: not only does it achieve a high cellular density akin to that of human organs, but the matrix’s viscosity also enables printing of a pervasive network of perfusable channels within it to mimic the blood vessels that support human organs,” said co-first author Sébastien Uzel, Ph.D., a Research Associate at the Wyss Institute and SEAS.
This video shows the SWIFT bioprinting process, including forming dense organ building blocks of living cells, printing and evacuating of sacrificial gelatin ink, and creating cardiac tissue that successfully beats like a living heart over a seven-day period.
When the cold matrix is heated to 37 °C, it stiffens to become more solid (like an omelet being cooked) while the gelatin ink melts and can be washed out, leaving behind a network of channels embedded within the tissue construct that can be perfused with oxygenated media to nourish the cells. The researchers were able to vary the diameter of the channels from 400 micrometers to 1 millimeter, and seamlessly connected them to form branching vascular networks within the tissues.
Organ-specific tissues that were printed with embedded vascular channels using SWIFT and perfused in this manner remained viable, while tissues grown without these channels experienced cell death in their cores within 12 hours. To see whether the tissues displayed organ-specific functions, the team printed, evacuated, and perfused a branching channel architecture into a matrix consisting of heart-derived cells and flowed media through the channels for over a week. During that time, the cardiac OBBs fused together to form a more solid cardiac tissue whose contractions became more synchronous and over 20 times stronger, mimicking key features of a human heart.
“Our SWIFT biomanufacturing method is highly effective at creating organ-specific tissues at scale from OBBs ranging from aggregates of primary cells to stem-cell-derived organoids,” said corresponding author Jennifer Lewis, Sc.D., who is a Core Faculty Member at the Wyss Institute as well as the Hansjörg Wyss Professor of Biologically Inspired Engineering at SEAS. “By integrating recent advances from stem-cell researchers with the bioprinting methods developed by my lab, we believe SWIFT will greatly advance the field of organ engineering around the world.”
Collaborations are underway with Wyss Institute faculty members Chris Chen, M.D., Ph.D. at Boston University and Sangeeta Bhatia, M.D., Ph.D., at MIT to implant these tissues into animal models and explore their host integration, as part of the 3D Organ Engineering Initiative co-led by Lewis and Chris Chen.
“The ability to support living human tissues with vascular channels is a huge step toward the goal of creating functional human organs outside of the body,” said Wyss Institute Founding Director Donald Ingber, M.D., Ph.D., who is also the Judah Folkman Professor of Vascular Biology at HMS, the Vascular Biology Program at Boston Children’s Hospital, and Professor of Bioengineering at SEAS. “We continue to be impressed by the achievements in Jennifer’s lab including this research, which ultimately has the potential to dramatically improve both organ engineering and the lifespans of patients whose own organs are failing,”
Learn more: A swifter way towards 3D-printed organs
The Latest on: 3D-printed organs
via Google News
The Latest on: 3D-printed organs
- Top Companies in 3D Bioprinting Market | Size and Share Analysis, Future Technology, Application and Global 3d Organ Printing Industry Trends By 2023 on November 18, 2019 at 3:45 am
This is chiefly on account of the growing demand for organs among the patient pool, the presence of developed healthcare infrastructure, and increasing investments in R&D activities. Moreover, the ...
- This Boat Was 3D Printed—and Bigger, Wilder Projects Will Soon Follow on November 14, 2019 at 6:00 am
One recent project uses a building block approach to creating whole organs. Much-famed Beyond Meat is soon going ... the start-up ICON showcased just that in the form of a 650-square-foot 3D printed ...
- Stratasys 3D-prints replicas of human hearts and other organs for surgery preparation and research on November 13, 2019 at 12:17 pm
Stratsys doesn’t build 3D-printed implants; it’s 3D printers concentrate on creating exact replicas that can be used in teaching hospitals and for inspecting organs before an operation. Ben Darling, ...
- Researchers have prototyped a technique that will quicken 3D printing significantly on November 13, 2019 at 10:00 am
A couple of months back, a team working at the Wyss Institute at Harvard developed an engineering solution—SWIFT—that endeavored to make 3D-printed organs more viable. With it, the researchers were ...
- Rock ‘n Roll With 3D-Printed Tonewheels on November 7, 2019 at 1:05 pm
He’s made a proof of concept for a DIY tone generator, which is the same revolutionary system that made the Hammond organ sing. Whereas the Hammond has one tonewheel per note, this project uses ...
- Liquid-in-liquid printing method could put 3D-printed organs in reach on November 1, 2019 at 4:47 pm
3D-printed tissues and organs could revolutionize transplants, drug screens, and lab models—but replicating complicated body parts such as gastric tracts, windpipes, and blood vessels is a major ...
- Sacrificial Ink Writing Technique for 3D Printed Organs on September 9, 2019 at 6:56 am
Researchers at Harvard have developed a way to 3D print vascular channels in large matrices composed of stem cell-derived organ building blocks. The technique could pave the way for 3D-printed organs.
- Harvard researchers have found a way to make 3D-printed organs more viable on September 6, 2019 at 11:14 pm
It will be interesting to see how the future of 3D printed organs pans out given that it's still early days for the field. The team of researchers at Wyss, whose aim is to engineer complete organ ...
- A swifter way towards 3D-printed organs on September 6, 2019 at 4:44 pm
However, all 3D-printed human tissues to date lack the cellular density and organ-level functions required for them to be used in organ repair and replacement. Now, a new technique called SWIFT ...
- 3D-printed organs are in early research stages. Here’s how Baltimore doctors are using the technology on August 17, 2019 at 9:47 pm
But using 3D-printed models of her heart ... Research into printing human organs is in the beginning stages. The 3D printers that layer powder and liquid versions of plastics, ceramics and metals have ...
via Bing News