Scientists at University College London are developing a way of spraying heart cells onto damaged hearts to help them beat.  The cells will, in the future, be taken from a patient, cultured in a lab, and then sprayed back into the heart.  They can already create a patch in the lab that beats just like regular heart muscle.

The catch?  Well, apart from the fact they haven’t even tested it on mice yet, let alone something more human-like, it involves 10,000 volts of electricity.  Not much room for error there!