I wonder, Bob, isn't there a 3D fabricator copier now, and could the matrices be stratified to lay down varying lines of cells in layer upon layer as the 3D construct occurs? ... BTW, I'm using an already existing fluid and technology for 'oxygenation' in Evil Interrupted.
The current technology for three-D reproduction is a tank of light-activated plastic. You expose the surface of the liquid to ultraviolet light which hardens the liquid, then you lower the surface, allowing more liquid to cover the freshly hardened suface, and expose that to a fresh layer of ultraviloet light patterning.
Over time, you have produced a three-dimensional reproduction of whatever was in the computer's memory.
The next step to take is to be able to print the colonizing cells into a nourishing three-dimensional structure, complete with its own blood flow and skeletal integrity.
Who wants to be first to have a head transplant?
(Just kidding -- the above would not allow for reproducing the structure of memory and interneural connections. It might suffice for some cruder substructures, however.)