For Immediate Release:August 27, 2012
New tissue scaffold could be used for drug development and implantable therapeutic devices.
CAMBRIDGE, Mass. — To control the three-dimensional shape of engineered tissue, researchers grow cells on tiny, sponge-like scaffolds. These devices can be implanted into patients or used in the lab to study tissue responses to potential drugs.
A team of researchers from MIT, Harvard University and Boston Children’s Hospital has now added a new element to tissue scaffolds: electronic sensors. These sensors, made of silicon nanowires, could be used to monitor electrical activity in the tissue surrounding the scaffold, control drug release or screen drug candidates for their effects on the beating of heart tissue.
The research, published online Aug. 26 in Nature Materials, could also pave the way for development of tissue-engineered hearts, says Robert Langer, the David H. Koch Institute Professor at MIT and a senior author of the paper.
“We are very excited about this study,” Langer says. “It brings us one step closer to someday creating a tissue-engineered heart, and it shows how novel nanomaterials can play a role in this field.”
Lead authors of the paper are Bozhi Tian, a former postdoc at MIT and Children’s Hospital; Jia Liu, a Harvard graduate student; and Tal Dvir, a former MIT postdoc. Other senior authors are Daniel Kohane, director of the Laboratory for Biomaterials and Drug Delivery at Children’s Hospital, and Charles Lieber, a Harvard professor of chemistry.
A 3-D system
Until now, the only cellular platforms that incorporated electronic sensors consisted of flat layers of cells grown on planar metal electrodes or transistors. Those two-dimensional systems do not accurately replicate natural tissue, so the research team set out to design a 3-D scaffold that could monitor electrical activity, allowing them to see how cells inside the structure would respond to specific drugs.
The team chose silicon nanowires for electronic sensors because they are small, stable, can be safely implanted into living tissue and are more electrically sensitive than metal electrodes. The nanowires, which range in diameter from 30 to 80 nanometers (about 1,000 times smaller than a human hair), can detect voltages less than one-thousandth of a watt, which is the level of electricity that might be seen in a cell.
The research was funded by the National Institutes of Health, the McKnight Foundation and Boston Children’s Hospital.
Written by: Anne Trafton, MIT News Office