The hope that it would be possible to produce human organs using 3D printers has been around for as long as the devices themselves. Although some progress had been made, there was still the problem of how to attach the transplant to the cardiovascular system in the human body. “Nearly all types of tissue and organs require blood vessels to survive and function,” explains Professor Shaochen Chen from the University of California in San Diego. For this reason, he and his team developed a 3D printing process, which allows an entire network of blood vessels to be produced for the first time.
To do this, a computer breaks down the 3D model of a blood vessel system into minute individual images, which it then conveys to millions of microscopically small mirrors. Using UV light, these mirrors project the photographs into a chemical solution containing both living cells and polymers. The light cures the solutions. Using this method, the model is printed in layers, producing a 3D polymer mesh that encloses the living cells. The latter grows and merges within a day, ultimately forming the finished blood vessel.
Blood vessels could save 175,000 lives a year
While existing processes can only print a single vessel, and take hours to do so, the new method produces a delicately branching network of blood vessels in a few seconds. “By contrast, other 3D printing technologies produce structures that could be described as pixelated,” says Wei Zhu from Chen’s team of researchers. Blood vessels that are collectively as thick as twelve human hairs are produced on a surface of four by five millimeters. In addition, the new method is more economical than earlier technologies and is based on materials that are biocompatible.
In contrast to earlier procedures, the artificially produced blood vessels can therefore be integrated into the circulatory system in the human body without issue. In future, the 3D printer will work with stem cells obtained from the individual patient to prevent the immune system from triggering a rejection response. The scientists want to test their discovery in clinical trials in a few years. If these trials are successful, the procedure could save around 175,000 people per year. These patients would not have to go on a transplant list, but would instead receive a new organ—including blood vessels—from the 3D printer.