One of the staples of science fiction is embedding the human
body with sensors, to merge humans and machines. That goal may be a bit closer.
A team of chemists and anesthesiologists has found a way to embed
nanometer-scale wires into living tissue. When implanted into a body, the "cyborg" tissue could potentially sense and monitor medicine or inflammation and keep doctors aware of whether the transplant is working.
The scientists started with a mesh of
silicon wires coated in an organic polymer, each 30 to 80 nanometers in diameter. The mesh is three-dimensional, like a sponge, and
can be bent into any shape. Next, the scientists seeded the mesh with living cells that were grown in a culture. The result was living cells with a three-dimensional mechanical support able to carry electrical signals. While two-dimensional scaffolds have been made before, those don't replicate what happens in the human body, where cells are in three-dimensional structures.
Thus far the team has engineered cyborg tissues using heart, muscle, blood vessel and nerve
cells. The cells' viability and activity wasn't affected. The embedded sensory circuits were able to pick up electrical signals generated by the cells in response to drugs. In the case of the blood vessels, the circuits
detected pH changes, which could be useful in tracking inflammation.
None of these pieces of tissue has been implanted into a human being yet; it will be some time before the technology gets to that point.
The team was led by Charles M. Lieber, a professor of chemistry at Harvard and
Daniel Kohane, a Harvard Medical School anesthesiologist. Kohane developed the
"scaffolds" for the cells. Other contributors were Robert Langer from
the Massachusetts Institute of Technology, and Zhigang Suo, professor of
mechanics and materials at Harvard. The work was published Aug. 26 in Nature
Materials.
Credit: Charles M. Lieber and Daniel S. Kohane, MIT
