A tool developed by Australian researchers could completely change the way surgeons repair injuries and defects to cartilage and bone. The BioPen is essentially a biological 3Doodler - it allows surgeons to draw with a bioink directly onto the surface of a bone during surgery. The ink, comprised of stem cells in a hydrogel solution, would then multiply inside the body, growing into new tissue. So far, the pen has shown a more than 97% success rate in testing. Read more at 3DPrint.com: https://3dprint.com/127916/biopen-3d-bioprinting-pen/