August 28, 2012
Electronic Sensors Paving Way For Tissue Engineered Hearts
Lee Rannals for redOrbit.com - Your Universe Online
Researchers have added electronic sensors to engineered tissue, potentially paving the way for tissue-engineered hearts.
Scientists reported in the journal Nature Materials that they have added electronic sensors to lab grown cells. These sensors 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.
“We are very excited about this study,” Robert Langer, the David H. Koch Institute Professor at MIT and a senior author of the paper, said in a prepared statement. “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.”
The team essentially set out to design a 3D scaffold that could monitor electrical activity, which would allow them to see how cells would respond to specific drugs.
They built the scaffold out of epoxy, and used silicon nanowires to carry electrical signals to and from cells grown within the structure.
“The scaffold is not just a mechanical support for cells, it contains multiple sensors. We seed cells into the scaffold and eventually it becomes a 3-D engineered tissue,” Bozhi Tian, a former postdoc at MIT, said.
The team said they used their scaffolds to grow cardiac, neural and muscle tissue. They were able to monitor cells' response to noradrenalin, which is a stimulant that increases heart rate.
“This is a beautiful example of how nanoelectronics can be combined with tissue engineering to monitor the behavior of cells,” Gordana Vunjak-Novakovic, a professor of biomedical engineering at Columbia University who was not part of the research team, said.
The scientists also grew blood vessels with embedded electronic sensors that showed they could be used to measure pH changes within and outside the vessels. Devices like this could allow doctors to monitor inflammation or other biochemical events in patients who receive the implants.
The team ultimately wants to engineer tissues that cannot only sense an electrical or chemical event, but also respond to it appropriately.
“It could be a closed feedback loop, much as our autonomic nervous system is,” Daniel Kohane, director of the Laboratory for Biomaterials and Drug Delivery at Children´s Hospital, said. “The nervous system senses changes in some part of the body and sends a message to the central nervous system, which then sends a message back to take corrective action.”