Dial Up an Ear: Tissue Engineers Bio-Print Body Parts

3D-printing is all the rage if you are a cosplayer looking to make Skyrim armor for your next convention, but regenerative medicine scientists at Wake Forest Baptist Medical Center have taken that ball and run it off the field. Using a custom-designed 3D printer, a team of researchers there have just proven that it is feasible to print living tissue structures to replace injured or diseased tissue in patients!

The team has printed ear, bone and muscle structures that, when implanted in animals, matured into functional tissue and developed a system of blood vessels. Significantly, these results indicate that the structures have the right size, strength and function for use in humans.

“This novel tissue and organ printer is an important advance in our quest to make replacement tissue for patients,” said Anthony Atala, M.D., director of the Wake Forest Institute for Regenerative Medicine and senior author on the study. “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.”

Atala and his team are “tissue engineers.” Their job is grow replacement tissues and organs in the laboratory to help solve the shortage of donated tissue available for transplants. 

The precision of 3D printing makes it a promising method for replicating the body’s complex tissues and organs, but your normal run-of-the-mill 3D printers cannot produce structures with sufficient size or strength to implant in the body.

The Integrated Tissue and Organ Printing System (ITOP), developed over a 10-year period by scientists at the Institute for Regenerative Medicine, overcomes these challenges. The system deposits both bio-degradable, plastic-like materials to form the tissue “shape” and water-based gels that contain the cells. In addition, a strong, temporary outer structure is formed.

To make this work, tissue engineers needed to make sure that implanted structures would live long enough to integrate with the body. The Wake Forest Baptist scientists addressed this in two ways. They optimized the water-based “ink” that holds the cells so that it promotes cell health and growth and they printed a lattice of micro-channels throughout the structures. These channels allow nutrients and oxygen from the body to diffuse into the structures and keep them live while they develop a system of blood vessels.

“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,” said Atala.