One of the most fruitful potential applications for 3D printing in healthcare is bioprinting, the production of living tissues. It’s raised quite a fuss considering the implications for printing of tissue constructs, grafts, and some time far off in the future, complete organs. There may be another breakthrough on the horizon – Chinese biotech company Sichuan Revotek Co. claims that their custom-made 3D bioprinter is capable of producing blood vessel systems, complete with hollow structures and layers of different cells.
The company’s chairman Yang Keng declared that their system is comprised of a medical imaging cloud platform, biological inks, a 3D bioprinter, and post-print processing system. It is apparently able to print a 10 cm blood vessel in only two minutes.
The key to the whole system, according to Revotek, are the Biosynsphere “bio-bricks.” These are designed to offer patient-specific stem cell bioprinting, and consist of “seed cells” (stem cells and differentiated cells) along with bio-inks chock full of growth factors and nutrients. Combined with other materials, the printer can produce layered cell structures, eventually cultivated into tissues.
One major challenge for 3D bioprinting is that the cells need to be kept alive and healthy throughout the fabrication process to generate viable tissue constructs. The leader of Revotek’s research team, Professor Kang Yu Jian, reports that they have engineered a solution: “We create special environmental and biological conditions for our bio-bricks, making it possible to differentiate the cells as we need. So we can print each layer with different cell.”
Jian also explains the importance of controlling in vitro stem cells to realize 3D bioprinting’s ultimate goal: complete organs. “Constructing any organ requires vessels that transport nutrients to them, and with this ‘bio-brick’ technology we have successfully achieved vessel revascularization with help of this 3D bio-printer,” he said.
Revotek plans in the near future to invest in companies all around the world, importing their bioprinting technologies, regenerative medicines, as well as personnel and laboratories.
As the first 3D bioprinter of its kind, it’s certainly exciting that Revotek has addressed the issue of creating a viable bio-ink. The cells apparently stay active because their temperature and environment are constantly regulated and nutrients and other active materials are supplied. However, another issue of bioprinting remains that even if the building materials are sturdy, the building itself might not be – which is certainly an issue considering that these blood vessels won’t just be for show.
Printing complex organic structures (like blood vessels) sometimes fails because the constructs collapse under their own weight before they solidify. This has been addressed to some degree with a fluid-to-solid state shifting gel that acts as scaffold during the printing process. Revotek hasn’t made it clear whether they have a similar approach to ensuring their blood vessels remain intact, other than the presence of a “post-print processing system” that’s included in the package.
Revotek has “mastered the stem cell-based 3D bioprinting technology,” according to Keng. If blood vessels are being produced as easily as Revotek claims, that’s a fantastic breakthrough; but it’s still only half the battle if bioprinting is to become a viable treatment. There’s no word yet on any patient trials using the printed blood vessels – there probably won’t be for quite some time, depending on China’s regulatory framework. Until then it’s unfortunately only a momentous potential leap in the technology, but I’ll be interested to see how the blood vessels (literally) hold up inside a patient.
