|Completed ear structure printed with the Integrated Tissue-Organ Printing System--Courtesy of Wake Forest University|
Scientists from Wake Forest Baptist Medical Center have proven that they can 3-D print living tissue structures, including ear, bone and muscle, which may be used to replace tissue on human patients. The research team published a paper in the journal Nature Biotechnology showing that they were able to 3-D print human-scale tissues and then effectively implant them in mice to result in vascularized, functional tissue.
Up next, researchers will need to demonstrate the viability of these structures in humans, as well as to advance more sophisticated tissue structures such as human organs. But early results demonstrate that these tissues have the correct size, strength and function for use in humans. Ongoing studies are being conducted to examine long-term outcomes. The research was backed by the Armed Forces Institute of Regenerative Medicine, a federally funded effort to apply regenerative medicine to battlefield injuries.
"This novel tissue and organ printer is an important advance in our quest to make replacement tissue for patients," said Dr. Anthony Atala, director of the Wake Forest Institute for Regenerative Medicine and senior author on the study in a statement. "It can fabricate stable, human-scale tissue of any shape. With further development, this technology could potentially be used to print living tissue and organ structures for surgical implantation."
It took researchers 10 years to develop the Integrated Tissue and Organ Printing (ITOP) System that printed these tissues at the Institute for Regenerative Medicine. Unlike traditional 3-D printing that operates via jetting, extrusion or laser-induced forward transfer, the ITOP system deposits both biodegradable, plastic-like material to for tissue shape and water-based gels that contain the particular cells.
The researchers made tissue structures with vessel-like structures that were smaller than 200 microns (0.007 inches) to help the cells to survive. In the study, they created a baby-sized ear structure of 1.5 inches that was implanted on a mouse and showed signs of vascularization one and two months after implantation as well as maintained its shape.
The ITOP system can use imaging data from CT and MRI scans to create custom tissue designed for an individual patient.
The 3-D printed muscle tissue was implanted into rats and after two weeks was found robust enough to keep its structure, become vascularized and induce nerve formation. While the bone structure was of jaw bone fragments printed using human stem cells. They were of a size and shape to be used in human facial reconstruction. After 5 months of implantation in rats, they had formed vascularized bone tissue.
"Our results indicate that the bio-ink combination we used, combined with the micro-channels, provides the right environment to keep the cells alive and to support cell and tissue growth," summed up Atala.
- here is the announcement and the study