Researchers have shown that 3D printed templates can be used to rapidly create vasculature and improve engineered living tissues.
Without a vascular system—a highway for delivering nutrients and removing waste products—living cells on the inside of a 3D tissue structure quickly die. Thin tissues grown from a few layers of cells don’t have this problem, as all of the cells have direct access to nutrients and oxygen.
Bioengineers have therefore explored 3D printing as a way to prototype tissues containing large volumes of living cells.
The most commonly explored techniques are layer-by-layer fabrication, or bioprinting, where single layers or droplets of cells and gel are created and then assembled together one drop at a time, somewhat like building a stack of LEGOs.