*NEWS*BODY PARTS MADE FROM PAPER

[Anonymous]

Body parts made from paper
dec 2005
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.
Repairing tissue
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

[Author]

December 6, 2005 at 10:49 AM