Wiring Up Engineered Tissue
This is interesting, the early stirrings of something that may change the tenor of future tissue engineering if carried through to its logical conclusions. Why build a plain heart if you can build a sensor-laden heart with its own embedded network for monitoring and medical intervention? From the release: "A multi-institutional research team has developed a method for embedding networks of biocompatible nanoscale wires within engineered tissues. These networks - which mark the first time that electronics and tissue have been truly merged in 3D - allow direct tissue sensing and potentially stimulation, a potential boon for development of engineered tissues that incorporate capabilities for monitoring and stimulation, and of devices for screening new drugs. ... One of the major challenges in developing bioengineered tissues is creating systems to sense what is going on (e.g., chemically, electrically) within a tissue after it has been grown and/or implanted. Similarly, researchers have struggled to develop methods to directly stimulate engineered tissues and measure cellular reactions. ... In the body, the autonomic nervous system keeps track of pH, chemistry, oxygen and other factors, and triggers responses as needed. We need to be able to mimic the kind of intrinsic feedback loops the body has evolved in order to maintain fine control at the cellular and tissue level. ... With the autonomic nervous system as inspiration, [scientists] built mesh-like networks of nanoscale silicon wires - about 80 nm in diameter - shaped like flat planes or in a 'cotton-candy'-like reticular conformation. The networks were porous enough to allow the team to seed them with cells and encourage those cells to grow in 3D cultures. ... Previous efforts to create bioengineered sensing networks have focused on 2D layouts, where culture cells grow on top of electronic components, or on conformal layouts where probes are placed on tissue surfaces. It is desirable to have an accurate picture of cellular behavior within the 3D structure of a tissue, and it is also important to have nanoscale probes to avoid disruption of either cellular or tissue architecture."
Link: http://www.eurekalert.org/pub_releases/2012-08/bch-rdm082412.php