Bioprinter creates human tissues and organs for transplant

Researchers at the Wake Forest Institute for Regenerative Medicine have built a 3D bioprinting system capable of generating living tissue and entire body parts to be used in transplant surgery.

While the scarcity of compatible organ donors has created a high demand for synthetic alternatives, engineering tissues suitable for human use has been slow going: until now, those more than 100-200 μM in diameter have been unable to survive. Anthony Atala’s team have resolved this problem by introducing microchannels to facilitate diffusion, giving cells access to the nutrients and oxygen they need. These microchannels, combined with synthetic polymers, lend the integrated tissue-organ printer (ITOP)’s products a level of structural integrity never seen before.

To put their bioprinter to the test, the team used rabbit cells and a CT scan of a human ear to fabricate human ear-shaped cartilage. When these ears were surgically implanted in mice, formation of tissue and blood vessels was observed within two months; in a similar experiment, it took just two weeks for nerve formation in transplanted muscle tissue in rats. With patient cells harvested from a small tissue biopsy and CT/MRI scans as a blueprint to dictate the structure, these methods could be applied to recreate healthy, “bespoke” body parts for those who need them, with an emphasis on repairing battlefield injury.

Much remains to be done before this technique can be employed in humans. But by pushing the boundaries of bioprinting and increasing both the size and stability of engineered tissues, the ITOP represents a key advance that could yield viable surgical implants with a minimal risk of rejection by the patient’s immune system. As Atala et al. concluded in their report in Nature Biotechnology, “With further development, this technology may produce clinically useful tissues and organs [that] recapitulate native structure and function.”

Photo: Wake Forest Institute for Regenerative Medicine