Engineered tissues and organs have been grown with various degrees of success in labs for many years. Many of them have used a scaffolding approach where cells are seeded onto biodegradable supportive structures that provide the underlying architecture of the organ or tissue desired.
But scaffolds can be problematic — ultimately, they should degrade and disappear, but timing that decomposition to coincide with the maturation of the organ is tricky, and sometimes degradation byproducts can be toxic. Scaffolds also can interfere with the development of cell-to-cell connections, which are important for the formation of functional tissues.
Now, a research team led by Eben Alsberg, the Richard and Loan Hill Professor of Bioengineering and Orthopaedics at the University of Illinois at Chicago, has developed a process that enables 3D printing of biological tissues without scaffolds using “ink” made up of only stem cells. They report their results in the journal Materials Horizons.
“Our cell only printing platform allows for the 3D printing of cells without a classical scaffold support using a temporary hydrogel bead bath in which printing takes place,” Alsberg said.
Above: Bioprinting the letter “C” using a stem cell only ‘bioink’ into an alginate microbead supporting medium. Video courtesy of Oju Jeon and Eben Alsberg, University of Illinois at Chicago
The micron-scale hydrogel beads allow the nozzle of the 3D printer to move through it and deposit cells with minimal resistance to that nozzle movement or the ejection of the cells. The gel beads support the cells as they are printed and keeps them in place and preserves their shape.
Once the cells are printed into the hydrogel bead matrix, it is exposed to UV light, which cross-links the beads together, in effect freezing them in place. This lets the printed cells connect with each other, mature and grow within a stable structure. The media that bathes the cells flows easily through the cross-linked gel beads and can be changed out as needed to provide fresh nutrients and dispose of waste products made by the cells. The hydrogel beads can be removed through gentle agitation, or controlling their degradation, leaving the intact tissue behind.
“The hydrogel bead bath has unique properties which allow for both printing of the cell-only bioink in complex architectures, and subsequent temporary stabilization of these cell-only structures to allow for cell-cell junctions to form,” Alsberg said. “Using chemistry we can then regulate when the beads go away.”
The cells Alsberg’s team used are stem cells — those that can differentiate into a wide variety of other cell types. They used the stem cells to 3D print a cartilage ear and a rodent-sized “femur” in the hydrogel bead bath. The cells they printed were able to form stable, cell-cell connections through specialized proteins.
“For the first time, cell-only constructs can be printed in intricate forms that are made up of different cell types without a hydrogel carrier or traditional scaffold that can then be stabilized for a period of a day to weeks. We’ve demonstrated that individual cells and cell aggregates can be organized and assembled using this platform strategy to form larger functional tissues, which may be valuable for tissue engineering, drug screening and as models to study developmental biology,” Alsberg said.
Oju Jeon, Yu Bin Lee, Sang Jin Lee, and Derrick Wells of the bioengineering department at the University of Illinois at Chicago and Hyoen Jeong of Case Western Reserve University, are co-authors on the paper.
The Latest on: 3D printed tissues and organs
via Google News
The Latest on: 3D printed tissues and organs
- Simulated 3D Print Model Of Heart equates Natural Organon February 24, 2021 at 10:27 am
Simulated 3D print model of human organs may help surgeons train and practice before they cut into a patient. This highlights the feasibility of the method in printing other realistic organ models, ...
- 3D-Printed Tissues Could Help Heal Serious Sports Injurieson February 17, 2021 at 4:00 pm
3D bioprinting already has come a long way, with researchers across the globe successfully printing live human tissue and complex circulatory systems for creating artificial skin and even organs. Now ...
- 3D Printing Technique Brings Hollywood to Human Organson February 17, 2021 at 4:00 pm
Researchers have been using 3D printing in medical applications for some time, but most of the time it’s been used to create devices like prosthetics for use outside the body. Now, a team of ...
- Cross-faculty team win funding challenge to study tissue regeneration using organ-on-a-chip technologyon February 17, 2021 at 5:22 am
A team of interdisciplinary researchers from Queen Mary University of London’s Barts and The London School of Medicine and Dentistry are one of three awardees for Phase 1 funding of the NC3Rs CRACK IT ...
- 3D bioprinting paves way for functional adult-sized tissues and organson February 16, 2021 at 8:17 pm
Research into 3D bioprinting has grown rapidly in recent years as scientists seek to re-create the structure and function of complex biological systems from human tissues to entire organs.
- FRESH 3D Printing Approach Paves the Way for Tissue and Organ Biofabricationon February 16, 2021 at 4:00 pm
Researchers from Carnegie Mellon University provide perspective on the FRESH 3D bioprinting approach, which prevents the distortion of bioinks by printing within a yield-stress support bath that holds ...
- Study: New approach to 3D printing of human tissue closer to realityon February 16, 2021 at 11:28 am
A new approach to 3D bioprinting has overcome the shortcomings associated with earlier versions of the technology, bringing the method of creating human tissue and organs one step closer to reality.
- FRESH 3-D-printing platform paves way for tissues, organson February 16, 2021 at 8:11 am
"Our goal is to be able to FRESH 3-D-print complex 3-D tissue and organ models out of a wide range of biocompatible hydrogel and cell-laden bioinks," said author Adam Feinberg. The FRESH technique ...
- FRESH 3D-printing platform paves way for tissues, organson February 16, 2021 at 8:03 am
Research into 3D bioprinting has grown rapidly in recent years as scientists seek to re-create the structure and function of complex biological systems from human tissues to entire organs. In APL ...
- Breakthroughs In 3D-Printed Transplantable Organs Have 3D Systems Expanding Its Investment In Regenerative Medicineon February 16, 2021 at 6:22 am
With its bioprinting collaboration with United Therapeutics showing huge promise, the pioneering AM company is doubling down on their bet.
via Bing News