Hopes for easier and more affordable transplant surgeries are getting higher thanks to a new bio-printer able to use living cells to 3D print body parts. US researchers described on Nature Biotechnology how they used this technique to grow ear, bone and muscle structures out of plastic-like materials and living cells matching those of humans, rats, mice and rabbits. The living cells would act as ink making it possible to produce human tissue in the laboratory.
Until now this technology has been tested only on animals, and if it will be successful also for humans it will represent a game-changer for transplants. Bio-printers could be used to replace cartilage and bones of injured patients using their own cells. Scientists have been researching in this area for at least two decades, but never reached reliable systems. An Australian company already developed a 3D printer brain tissue but the structure resulted to be unstable and too simple to be implanted in humans. However thanks to this sophisticated, custom-designed printer this doesn't seem to be a problem anymore.
It took a decade for the Wake Forest Institute for Regenerative Medicine team to come up with their new bio-printer, called ITOP: Integrated Tissue and Organ Printing System. This revolutionary printer creates the structures by layering patterns of cell-containing gels and biodegradable, plastic-like mass. Then a temporary pouter shell made of polymer is added to help the structure to hold up throughout implantation. Once embedded in an organism the cells remain alive and the plastic-like material gradually degrade. Meanwhile the cells secrete a supporting matrix to keep the structure shape. In this way the cells become self-sufficient and don't need any supporting material anymore. The new organs have the size, structure and dimension for human use and if transplanted they would be colonized by blood vessels and start to develop, mature and restore autonomously.
The researchers printed human-sized ears and implanted them in mice to examine the blood supply and the formation of cartilage tissue, which happened within two months. Then they embed muscle tissue in rats and were able to see nerve formation within two weeks.
The study was supported by the US Armed Forces Institute for Regenerative Medicine. Anthony Atala, director of the Wake Forest Institute at Winston-Salem in North Carolina, described the bio-printer as an essential technology: “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”.