Researchers from the University of California, San Diego, led by Professor Shaochen Chen, successfully 3D printed a framework of functional blood vessels, using a 3D bioprinting process.  Almost all tissues and organs need blood vessels to survive. This is a big bottleneck in making organ transplants, which are in high demand but in short supply, and 3D bioprinting blood vessels can help bridge this gap. (3D Printing Industry)