3D printed implants can prompt new bone to grow in animals, scientists reported today in the journal Science Translational Medicine. Called hyperelastic "bone," their new bioengineered material could also be cheap, versatile and easy to print and use for repairing or regenerating bones in people.

The grafts, which helped mend bone injuries in rats and monkeys, are made from hydroxyapatite, a mineral found in bones and teeth, and a biodegradable polymer. "Despite the fact that is majority ceramic, which is usually very brittle, it possesses very unique…properties that makes it highly elastic," coauthor Ramille Shah, of Northwestern University in Evanston, Illinois, said in a press conference on Tuesday. "When we squeezed or deformed it, it bounced right back to its original shape."

When Shah and her colleagues placed human stem cells taken from bone marrow on a sample of hyperelastic "bone," its mere presence was enough to prompt them to mature into bone cells (this type of stem cell can also make fat or cartilage). The "bone" scaffold served as a source for the cells to create their own natural materials, fellow team member Adam Jakus, also of Northwestern University, said in the press conference.