Scientists with the German Fraunhofer Institute have begun constructing artificial blood vessels thanks to an advanced 3D printing technique. Their research has the potential to radically change how transplants are handled, and could help end the long waiting lists of people in need of donated organs.
The team used a 3D ink-jet printer which constructed blood vessels by layering special inks. Unfortunately, existing 3D printing systems are still not sufficiently advanced to create the complex structure of blood vessels nor endow them with the necessary elasticity for them to function in a living body. That’s why the scientists used a process called two-photon polymerization in addition to printing.
From the Fraunhofer Institute:
Brief but intensive laser impulses impact the material and stimulate the molecules in a very small focus point so that crosslinking of the molecules occurs. The material becomes an elastic solid, due to the properties of the precursor molecules that have been adjusted by the chemists in the project team. In this way highly precise, elastic structures are built according to a 3-dimensional building plan.
Once built, the scientists needed to find a way to make the vessels integrate into existing body systems. To that end, they coated the vessels with “modified biomolecules” which should allow cells to “dock” with the vessels. When building the vessels, the ink used in the printing process was also imbued with these biomolecules as well.
While creating artificial blood vessels is valuable in its own right, the goal behind the research is to make artificially grown tissue more usable in human transplants. Grown organs and complex tissues often suffer from not having any means of being supplied with blood. Artificial blood vessels could give grown tissue the nourishing blood that it needs to grow. If successful, it could mean that patients in need of organ transplants could rely on sources other donations. According to Fraunhofer, there are 11,000 people currently on the waiting list for organs in Germany alone. With numbers like that, the dire need for transplants of any kind comes into sharp focus.