All the mechanicals work, they can easily change the ink to adult stem cells derived from the patient.
Yes.
At least in theory.
One thing about such a process is that the deposition is going to be very damaging to cells. But it doesn’t need 100% integrity to be effective, just enough cells. Even a 1% rate of intact cells could be effective.
The human embryonic stem cells are hardier than adult stem cells and can be obtained in much more plentiful numbers. So development with more safe and theoretically more effective adult stem cells won’t be easy.
Don’t get me wrong, I think this is a great idea that may work out well over time and help a lot of people.