Printing Organs on Demand
Posted December 24, 2005on:
Need a skin graft? A new trachea? A heart patch? Turn on your printer, and let it spit one out. A group of researchers hope printers’ whirs and buzzes will soon be saving lives.
Researchers at three universities have developed bio-ink and bio-paper that could make so-called organ printing a reality. So far, they’ve made tubes similar to human blood vessels and sheets of heart muscle cells, printed in three dimensions on a special printer.
While printed DNA and RNA chips have been around for a while, they have until now been printed in two dimensions, Forgacs said. Also, organ printing scientists have figured out how to print not just molecules, but clusters of cells, he said.
Here’s how it works: A customized milling machine prints a small sheet of bio-paper. This “paper” is a variable gel composed of modified gelatin and hyaluronan, a sugar-rich material. Bio-ink blots — each a little ball of cellular material a few hundred microns in diameter — are then printed onto the paper. The process is repeated as many times as needed, the sheets stacked on top of each other.
Once the stack is the right size — maybe two centimeters’ worth of sheets, each containing a ring of blots, for a tube resembling a blood vessel — printing stops. The stack is incubated in a bioreactor, where cells fuse with their neighbors in all directions. The bio-paper works as a scaffold to support and nurture cells, and should be eaten away by them or naturally degrade, researchers said.