It’s working ...
It started back in 2004. I was working in my office one day when suddenly I heard a roar from the adjacent lab. I rushed over, expecting to find someone dead or badly injured. Instead I saw a few of my students jubilantly gazing at a Petri dish stuck in the new three-dimensional printer we had received a few weeks back. They just managed to print a ring of cellular aggregates. These cellular aggregates -- we now call them bioink particles -- are composed of thousands of cells and placed into biocompatible gels, or biopaper.
This was the first time extended biological constructs, and not just individual cells, were deposited using an automatic delivery device. I remember closing my eyes for a few seconds and imagining how one day we were going to build blood vessels, hearts and kidneys from the patients’ own cells (called autologous tissue engineering) and solve the looming shortage of donor organs.
We are not yet there, but printing organs is not science fiction anymore. Several research groups have embarked on the exciting path of organ printing. Both redesigned desktop inkjet printers and mechanical extruders are being used for printing biological structures of growing complexity. We just write a computer script using architectural software, such as ArchiCAD, prepare the bioink and biopaper, and push a button; the rest is up to the bioprinter and nature. Once printed, the bioink particles fuse into a continuous structure.
Sounds easy.
But do not yet rush and load up with alcohol. It will take some time before your native liver can be replaced with a bioprinted one. Here is how we will get there. The first task is to print a vasculature -- the branching tree-like structure blood vessels form to deliver nutrients effectively to every cell and organ in the body. Without blood supply an engineered biological structure will not survive beyond a certain size, say a box with a side of half a millimeter, hardly a liver. Thus we spent the last three years learning how to print blood vessels. These are now close to being ready for insertion into an animal, and tested in coronary bypass surgeries. Once we know how to print single vessels, we can combine to build vascularized organs, such as the kidney or liver. Will the printed kidney look like the real one in all its details?
I doubt we will ever be able to reproduce what nature has been experimenting with for millions of years. The engineered kidney will not be a carbon copy of the one we are born with, but it will function just as fine if not better. And when this happens the first time, you know the rest.
About this Week's Guest Blogger:
Gabor Forgacs
George H. Vineyard Distinguished Professor of Biological Physics
Department of Physics, Biology and Biomedical Engineering
University of Missouri
* Visit the research websites:
http://forgacslab.missouri.edu
http://organprint.missouri.edu
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