I find this absolutely amazing. However, it makes no sense to me. I understand 3D printing, but I can’t make the jump to printing with cells.
How do they stay alive during the process?
How do they stick together?
How do they know how to keep their shape once they are stuck together?
How do they “know” how to work together to contract (and eventually to pump)?
So many things I don’t understand. Can of the biologists here help me out (even point me to some good reading).
The cells are kept and printed in media containing all the nutrients they need to stay alive. The process isn’t particularly mechanically taxing on them so they have no reason to die.
I may be wrong, but I think these cells basically just detect each other when they’re in close proximity and express adhesion proteins that stick them together.
They don’t “know” to, but they have no reason to change shape once they’re all stuck together in a particular arrangement.
About 1% of the cardiac cells spontaneously come to control electrical conductivity in the tissue, leading to videos like this one which shows some differentiated cardiac cells contracting together in a Petri dish: