What if you could press a button and a machine would make you a new nose or kidney, or any preferred body part? Scientists are exploring that futuristic vision by using special 3-D printers to make living body parts. Called bioprinters, these printers use human cells as “ink.”
A standard 3-D printer layers plastic to create items such as car parts, for example, but a bioprinter layers cells to form three-dimensional tissues and organs. Bioprinting originated in the early 2000s when it was discovered that living cells could be sprayed through the nozzles of inkjet printers without damaging them.
Today, using multiple print heads to squirt out different cell types, along with polymers that help keep the structure in shape, it is possible to deposit layer upon layer of cells that will bind together and grow into living, functional tissue.
Printed skin might eventually be employed for grafts—repairing burns and ulcers. There are also tests and plans being made to print skin directly onto the surface of the body. Renovacare, a firm in Pennsylvania, has developed a gun that will spray skin stem cells directly onto the wounds of burns victims.
Stem cells are cells that multiply to produce all of the cell types that a tissue is composed of. The stem cells in question will most likely come from the patient himself, meaning that there is no risk of his immune system rejecting the new tissue.
While the printing of skin may be great, the real prize for these scientists would be to be able to print entire organs. For kidneys, Roots Analysis, a medical-technology consultancy, predicts that this dream should be possible in about six years.
Livers, which have a natural tendency to regenerate anyway, should also arrive reasonably soon. Hearts, with their complex internal geometries, will take longer. In all cases, though, printed organs would mean that those awaiting transplants wouldn’t have to wait for the altruism of another or the death of a stranger to provide the means to save their own lives.