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A New Biopaper for Organ Printing
Roland Piquepaille writes "Organ printing is an emerging branch of medicine which uses healthy cells to repair a damaged or diseased organ. But as its name implies, this new medical technology needs ink, paper and a printer. Now, a new hydrogel -- or biopaper -- developed at the University of Utah has been selected by the National Science Foundation (NSF) to speed up this process. This five-year NSF study will initially try to print blood vessels and cardiovascular networks. But its real goal is to build some complex organs, such as livers or kidneys. This technology can potentially help millions of people waiting for transplants."
I assume this same technology could be used to print food. How about a 2 by 4 strip of fresh wood? A living cell replicator is actually going to be developed before a generic molecular replicator? Actually, it makes sense that this would be the case now that I think about it.
You can't use it to "print" a hamburger unless you use hamburger "ink." This thing takes cells as its raw material and basically layers them to make the tissue you want - they used the example of stacking donuts of cells, which grow together into a continuous blood vessel.
This only works because the cells are alive and can start functioning together. So you can't use it to make a wooden 2x4 or a beef patty or a sharktooth necklace or whatever. The bits wouldn't stick to each other because they wouldn't grow together if they're dead.
I don't know, but I have a guess based on tangential conversations with biologists: see, the problem is, how do you tell the cells, even if they're willing to divide and grow, to organize themselves into some macroscopic shape, like a sac with tubes and various layers? They don't response to yelled commands, you know. And each cell doesn't exactly have a Master Blueprint in its DNA with its own role marked off in red ink.
As much as I can tell, large organ growth in the living organism is directed by complex gradients of growth factors (chemicals), e.g. a low-to-high concentration of growth factor foo along a finger bud causes the bud to preferentially grow in the direction of the steepest increase in foo concentration -- i.e. along the long axis of the bud -- so the bud grows longer and not wider, all without any mythical "central authority" actually coordinating the activity of the cells.
But if you're trying to grow an organ in a tank, without any surrounding complex bath of growth factors et cetera, it's not likely the environment will be right to direct the growth of the cells, so you're just going to get a pile of unorganized flesh, not a fresh gleaming liver ready to plug in.
What I think they're doing here is figuring a way to direct the growth more or less by "lithography," i.e. by laying down one tiny layer at a time. You lay down a support matrix in the pattern you want the cells to form in this layer, let them grow, add another layer, rinse, repeat....by and by, you can construct any larger organized structure you want, layer by tiny layer. That's the point, I'm guessin.