A new trick invented by a team of scientists at University College London has greatly improved the chances for creating artificial tissue--they can weave threads made of stem cells into almost any shape. Ultimately this could lead to artificial transplants, with the resulting synthetic tissue able to adapt to many different purposes.
Stem cell research is centered around two things--trying to control what "real" cells to trick the cameieonic cells into becoming, and determining how to structure networks of the cells to create large-scale artificial tissue. There are a number of techniques for doing this, including ink-jet-like printing, but the new method can create "printed" line-based structures of embryonic stem cells for the very first time.
And interestingly it's a technique borrowed from the paint industry: electrospraying. Instead of directing a fluid through a nozzle simply using the force from compressed gas, electrospraying charges the fluid and accelerates it between the nozzle electrode and a distant "target" electrode--among other things, this allows for fine control of the spraying process.
In the UCL technique pioneered by Suwan Jayasinghe's research team, a solution of biodegradable polymer and embryonic stem cells are passed through an electrospray nozzle--in this design it's a nested arrangement of stainless-steel needles. The charged liquid is attracted toward another charged copper ring, and then emerges behind it as a very fine string or thread. By tracing this thread back and forth across a surface, the team can build up a flexible stemcell "fabric," with the viscous polymer holding the structure together. And the fabric doesn't have to be two-dimensional: by tracing matter over a mold any number of 3D-shapes can be produced. The team has tested the resultant artificial tissue matrix and confirmed that the electrospraying doesn't harm the stem cells, which can then consolidate and grow into living tissue.
This paves the way for artificial organs or even muscles--once the structure is "printed" chemical commands or environmental cues make the stem cells morph into the required body tissue and the biodegradable polymer is removed when it becomes superfluous.
It'll be decades before the technology matures to the point it's a routine procedure--assuming the ethical concerns are dealt with soon--but the possibility of "printing out" a new body part may one day move out of the realm of science fiction (remember that scene from Fifth Element?) and into science fact.
[via Integrative Biology ]