In the future, your heart could be repaired with gold nanowire cell patches. 
Researchers at MIT and Harvard University have developed tiny 
gold-studded scaffolds that can be used to build tissue in which cells 
have a synchronous beat, a possible repair tool for treating 
heart-attack victims.
In a study
 reported in Nature Nanotechnology, Daniel Kohane, a professor in the 
Harvard-MIT Division of Health Sciences and Technology (HST), and 
colleagues improved the electrical conductivity of scaffolds used to 
grow cardiac cells.
They devised a new scaffold material but based it on alginate, an 
organic substance that's already used in tissue scaffolds. They combined
 the alginate with a solution containing gold nanowires, which are good 
conductors.
After cardiac cells were seeded on the composite scaffold, the 
researchers compared the conductivity of the gold-enhanced cells with 
cells grown on regular alginate. They checked each for the presence of 
calcium, which helps electrical signals travel in the tissue.
In the vid below, calcium-labeled cells glow green. The gold-enhanced 
scaffold cells, pulsing together, showed a signal range enhanced by 
three orders of magnitude.
"Tissues grown on these composite matrices were thicker and better 
aligned than those grown on pristine alginate," the researchers wrote, 
"and when electrically stimulated, the cells in these tissues contracted
 synchronously."
Conduction was improved to a scale of many millimeters compared with a 
few hundred micrometers with regular alginate and several centimeters in
 normal heart tissue.
"It's really night and day. The performance that the scaffolds have with
 these nanomaterials is just much, much better," MIT quoted Kohane as 
saying.
The researchers plan to test the scaffolds in vivo next in the hopes of 
producing better heart patches, though the technology might also be used
 for muscle or nerve cells.