Researchers at Johns Hopkins University School of Medicine have developed a groundbreaking recipe for natural, 3D printable bone scaffolds, using a combination of man-made, biodegradable plastics and pulverized natural bone material. With this mix of ingredients, doctors could potentially 3D print replacement bones that could be implanted in the patient's body. The 3D printed bone would encourage natural regrowth, while slowly allowing the plastic scaffold to be naturally broken down and absorbed by the body. You can read more over on 3DPrint.com: https://3dprint.com/133158/3d-printable-bones/