3D printing technology is promising for the artificial organ. The circulatory and pulmonary systems such as liver or lung contain separate networks of channels that intertwine but do not intersect with each other, the printing of vascular with nutrient delivery function is a big challenge.
Grigoryan et al. show that natural and synthetic food dyes can be used as photoabsorbers that enable stereolithographic production of hydrogels containing intricate and functional vascular architectures, which speed up the absorption of special blue light. Researchers found the red cell can capture the oxygen when flowing in the 3D printing vascular, and after inserting the primary hepatocyte, the liver cells can live well in the body of mouse with chronic liver injury . This research is a great breakthrough of tissue engineering.