Researchers in the USA have designed a 3D printer that can build living cells around a biodegradable structure to construct various artificial tissues.
Scientists at the Wake Forest Institute for Regenerative Medicine (WFIRM), North Carolina, created bone, ear cartilage and skeletal-muscle structures using a custom-designed bioprinter.
'We are printing all kinds of things,' said Professor Anthony Atala, director of WFIRM and senior author on the study. '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,' he added.
The researchers used an 'integrated tissue-organ printer' to produce patient-specific artificial tissue constructs. The printer, which uses different cell types and synthetic polymers as 'ink', can trace a blueprint of a CT, computerised tomography or MRI, magnetic resonance imaging scan.
'The nozzles that we designed go down to 1/80th the diameter of a human hair,' said Professor Atala. The results, published in Nature Biotechnology, show that it may one day be possible to 'print' artificial tissues of any shape and size to repair or replace injured or diseased tissues and organs.
In an attempt to produce tissue that can survive long enough to be used in transplantation, the researchers created structures that contained small pores known as micro-channels. These channels allow nutrients and oxygen to flow, in order to sustain the cells while they develop their own network 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 Professor Atala, who has previously presented the idea of 3D printed organs at TED (technology, entertainment and design) conferences in 2009 and 2011.
Using animal models, the researchers have demonstrated that the reconstructed tissues are able to mature into functional tissues and develop their own blood supply and nerves. For example, five months after a bone fragment was implanted into rats, the researchers observed that the bioprinted structures integrated well and formed vascularised bone tissue.
'Demonstrating three different tissue-like structures, which they've implanted into animal models, is a great demonstrator of what can be achieved with current technology if you can package it all together in one unit,' Professor Brian Derby of the University of Manchester, who was not involved in the study, told Chemistry World.
The team acknowledges that further testing is required before the bioprinted tissues can become a clinical reality. 'We're now looking at the long-term viability and safety of the structures,' said Professor Atala.