Regenerative Medicine: 3-D Printing Tissue Moves Closer To The Clinic

A new report in Nature Biotechnology reveals 3-D printing living tissue is a feasible approach for use in regenerative medicine

Scientists at The Wake Forest Institute for Regenerative Medicine have used a custom designed 3-D printer to print muscle, bone and ear structures that mature into functional tissue when implanted into an animal; developing blood vessels and proving the structures can withstand transplantation. 

"This novel tissue and organ printer is an important advance in our quest to make replacement tissue for patients. 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"

The Integrated Tissue and Organ Printing System (ITOP)

Getting the right shape with a 3-D printer is relatively easy, but making sure its strong enough to survive and integrate with a host is far harder. In the ITOP system, the Wake Forest team coupled biodegradable plastics to create shape with a water-based ink to gel the cells in use to promote growth. They also printed micro-channels in the gel - allowing nutrition and oxygen to diffuse through the structure before blood vessels have developed. Previous results have suggested larger structures like an ear can't survive without 'ready made' blood vessels, but this research proved ITOP  can keep structures like a small ear alive while vessels form and mature after transplantation. 

Completed ear structure printed with the Integrated Tissue-Organ Printing System Credit: Wake Forest Institute for Regenerative Medicine

"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"

Exciting results

In several experiments, ITOP was proven able to create complex 3-D structures resembling various human tissues. When a human ear structure was implanted in mice, it retained its shape and formed cartilage and blood vessels too. Printed muscular tissue implanted into rats also survived the process and began to form a vascular network and nerve connections. 

In an even more exciting step, the team was able to print jaw bone fragments with stem cells that formed vascularised bone tissue after implantation - suggesting that one day a similar strategy could be incorporated for facial reconstruction. 

See the machine in action below:

Credit: Wake Forest Institute for Regenerative Medicine

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