Presently, if a patient is missing a section of bone due to accident or disease, it has to be replaced with bone harvested from elsewhere in their body. A new cell-containing gel, however, could one day be 3D printed right into the injury, where it would then harden.
First of all, there are already a variety of experimental materials that can be placed in a cavity where bone is missing. These serve as a sort of three-dimensional micro-structured scaffolding, which cells from the adjacent bone tissue gradually migrate into. Those cells proceed to reproduce, until they eventually replace the material with actual bone.
Seeking a faster alternative, scientists at Australia’s University of New South Wales-Sydney have created a calcium phosphate-based “bio-ink” gel that already contains the patient’s own live bone cells. In a technique known as ceramic omnidirectional bioprinting in cell-suspensions (COBICS), that non-toxic gel is 3D-printed directly into the patient’s bone deficit. It proceeds to harden – within minutes of exposure to their bodily fluids – forming into a bone-like material consisting of mechanically interlocked bone mineral nanocrystals.