BODY PARTS MADE FROM PAPER
BODY PARTS MADE FROM PAPER
2005-12-06 at 10:48:00 am #13204
Body parts made from paper
Thin sheet Cells are sprayed onto a special paper, the basis of a new type of tissue engineering.
Thin sheets of a gel-like material could help to turn out living tissues, blood vessels and organs, scientists say.
The research, reported in a recent issue of Physical Review Letters, represents a new branch of tissue engineering called organ printing.
This uses a printer and cell-laden ink to create spare tissues and organs, a technology that the researchers say could help millions of people worldwide.
“It’s basically enabling part of the technology. If you don’t have a good bio-paper and bio-ink, you’re not going to get anywhere,” says Professor Glenn Prestwich, of the University of Utah.
The idea behind organ printing is relatively simple: print cells onto thin sheets of biodegradable paper; stack thousands of sheets of the paper on top of each other; and when the paper disintegrates, the cells are left intact to form a 3D shape, such as a hollow blood vessel.
Different types of paper
Until now, scientists have tried different materials to use as the paper, including agarose, made from seaweed extract, and collagen, a protein found naturally in the body.
But agarose does not work well in organ printing because it does not biodegrade. And while collagen biodegrades, it has a tendency to contract and shrink, which makes it difficult to get nutrients in and out of the embedded cells.
The new bio-paper developed by Prestwich and his team from the University of Missouri and the Medical University of South Carolina biodegrades without shrinking.
It is made by connecting long molecular chains of sugar, forming a jelly-like hydrogel.
The cells are mixed with the gel and put into a standard inkjet printer cartridge. The machine then spits out a gel sheet embedded with cellular dots containing a minuscule amount, about 1 microliter each.
The bio-paper capitalises on the natural ability of cells to repair tissue.
Cells embedded into the bio-paper secrete enzymes that eat up the hydrogel; produce a biological matrix for new cells; and multiply and divide to create new cells. Eventually, the cells migrate, fuse together, and become a functioning tissue.
“Printing technology is really the next frontier in terms of the generation of tissues and organs,” says Dr Anthony Atala, director of the Wake Forest Institute for Regenerative Medicine at Wake Forest University.
Cells can already be painted by hand onto a biological scaffold.
“This is analogous to going from a handheld paint brush to an air brush,” he says.
The challenge is figuring out which printing method works best for which tissue and how best to incorporate the blood vessel network into the tissue to deliver nutrients to the cells.
To date, Prestwich, who is also the founder of Salt Lake City-based Sentrx Surgical, a company licensed to use this technology, and his team have been able to create tubular shapes like blood vessels.
He hopes that within three to six years, a version of this technology could be available to patients